a-z,A-Z,0-9. +/\*% <>~=& { } [|] ; : # ? , _ ' $ " @
.(separator)+/\*%(arithmetic)<>~=&*(Booleans){ }(dynamic array)[ | ](block closures);(cascade):(assignment, keywords)#(symbol and array)'(string)$(character)"(comment)@(point creation)- blank (
Character space), tab (Character tab), cr (Character space), lf (Character lf)
- variables must be declared before use surrounded by
|e.g.,| a b | - shared vars must begin with uppercase
- local vars must begin with lowercase
- reserved names:
nil,true,false,self,super, andthisContext
- Global: defined in a global namespace Smalltalk and accessible by all objects in system *
- Special: (reserved)
thisContext,super,self,true,false,nil - Method Temporary: local to a method
myMethod
| tmp1 temp2 |
...- Block Temporary: local to a block
[
| tmp1 temp2 |
... ]- Method Parameters: automatic local vars created as a result of message call with params
myMethod: myArg
...- Block Parameters: automatic local vars created as a result of value: message call
[ :each |
... ]- Instance Variables: unique to each instance
- Class: shared with all instances of one class & its subclasses
- Class Instance: unique to each instance of a class
- Classes are defined inside packages
- Methods are public and virtual
- By default a method returns the receiver
- Class methods are just methods of the class (i.e., public, virtual)
Comments are enclosed in quotes
"Comments are enclosed in quotes"Period (.) is the statement separator
self doThis.
self doThat| x y |
x := 5. "assignment"
x := y := z := 6. "compound assignment"
x := (y := 6) + 1.
x := Set new. "assign the newly created instance"
x := 123 class. "assign the object class"
x := Integer superclass. "assign the superclass of a class"
x := Object allInstances. "assign an array of all instances of a class"
x := Integer allSuperclasses. "assign all superclasses of a class"y := x copy. "copy object"
y := x deepCopy. "copy object and instance vars"| b |
b := true. "true constant"
b := false. "false constant"
x := nil. "nil object constant"
x := 1. "integer constants"
x := 8r177. "octal integer constant"
x := 3.14. "float constants"
x := 2r1010. "arbitrary base integer"
x := 2r1.1. "arbitrary base float"
x := 2r1.1e2. "float with exponent"
x := 2e-2. "fractional constants"
x := 16r0F. "hex constant".
x := 36rPHARO5. "number in base 36"
x := -1. "negative constants"
x := 'Hello'. "string constant"
x := 'I''m here'. "single quote escape"
x := $A. "character constant"
x := $ . "character constant (space)"
x := #aSymbol. "symbol constants"
x := #'It''s a symbol!'. "quoted symbol literal"
x := #(3 2 1). "array constants"
x := #[255 255 0]. "byte array constant"
x := #(2 2.0 #two two 'two' #($t $w $o) #[2 2]). "nested array literal"
x := #('abc' 2 $a). "mixing of types allowed"| b x y |
x := 1. y := 2.
b := x = y. "equals"
b := x ~= y. "not equals"
b := x == y. "identical"
b := x ~~ y. "not identical"
b := x > y. "greater than"
b := x < y. "less than"
b := x >= y. "greater than or equal"
b := x <= y. "less than or equal"
b := b not. "boolean not"
b := x < 5 & (y > 1). "boolean and"
b := x < 5 | (y > 1). "boolean or"
b := x < 5 and: [y > 1]. "boolean and (short-circuit)"
b := x < 5 or: [y > 1]. "boolean or (short-circuit)"
b := x < 5 eqv: (y > 1). "test if both true or both false"
b := x < 5 xor: (y > 1). "test if one true and other false"
b := 5 between: 3 and: 12. "between (inclusive)"
b := 123 isKindOf: Number. "test if object is class or subclass of"
b := 123 isMemberOf: SmallInteger. "test if object is type of class"
b := 123 respondsTo: sqrt. "test if object responds to message"
b := x isNil. "test if object is nil"
b := x isZero. "test if number is zero"
b := x positive. "test if number is positive"
b := x strictlyPositive. "test if number is greater than zero"
b := x negative. "test if number is negative"
b := x even. "test if number is even"
b := x odd. "test if number is odd"
b := x isLiteral. "test if literal constant"
b := x isInteger. "test if object is integer"
b := x isFloat. "test if object is float"
b := x isNumber. "test if object is number"
b := $A isUppercase. "test if upper case character"
b := $A isLowercase. "test if lower case character"| x |
x := 6 + 3. "addition"
x := 6 - 3. "subtraction"
x := 6 * 3. "multiplication"
x := 1 + 2 * 3. "evaluation always left to right (1 + 2) * 3"
x := 5 / 3. "division with fractional result"
x := 5.0 / 3.0. "division with float result"
x := 5.0 // 3.0. "integer divide"
x := 5.0 \\ 3.0. "integer remainder"
x := -5. "unary minus"
x := 5 sign. "numeric sign (1, -1 or 0)"
x := 5 negated. "negate receiver"
x := 1.2 integerPart. "integer part of number (1.0)"
x := 1.2 fractionPart. "fractional part of number (0.2)"
x := 5 reciprocal. "reciprocal function"
x := 6 * 3.1. "auto convert to float"
x := 5 squared. "square function"
x := 25 sqrt. "square root"
x := 5 raisedTo: 2. "power function"
x := 5 raisedToInteger: 2. "power function with integer"
x := 5 exp. "exponential"
x := -5 abs. "absolute value"
x := 3.99 rounded. "round"
x := 3.99 truncated. "truncate"
x := 3.99 roundTo: 1. "round to specified decimal places"
x := 3.99 truncateTo: 1. "truncate to specified decimal places"
x := 3.99 floor. "truncate"
x := 3.99 ceiling. "round up"
x := 5 factorial. "factorial"
x := -5 quo: 3. "integer divide rounded toward zero"
x := -5 rem: 3. "integer remainder rounded toward zero"
x := 28 gcd: 12. "greatest common denominator"
x := 28 lcm: 12. "least common multiple"
x := 100 ln. "natural logarithm"
x := 100 log. "base 10 logarithm"
x := 100 log: 10. "logarithm with specified base"
x := 100 floorLog: 10. "floor of the log"
x := 180 degreesToRadians. "convert degrees to radians"
x := 3.14 radiansToDegrees. "convert radians to degrees"
x := 0.7 sin. "sine"
x := 0.7 cos. "cosine"
x := 0.7 tan. "tangent"
x := 0.7 arcSin. "arcsine"
x := 0.7 arcCos. "arccosine"
x := 0.7 arcTan. "arctangent"
x := 10 max: 20. "get maximum of two numbers"
x := 10 min: 20. "get minimum of two numbers"
x := Float pi. "pi"
x := Float e. "exp constant"
x := Float infinity. "infinity"
x := Float nan. "not-a-number"
x := Random new next; yourself. x next. "random number stream (0.0 to 1.0)"
x := 100 atRandom. "quick random number"| b x |
x := 2r1111 bitAnd: 2r0100. "and bits"
x := 4r3333 bitAnd: 2r011011011. "and with different bases"
x := 2r1111 bitOr: 2r0100. "or bits"
x := 16rFF bitXor: 8r5252. "xor bits mixing bases"
x := 16rFF bitInvert. "invert bits"
x := 2r0100 bitShift: 2. "left shift"
x := 2r0100 bitShift: -2. "right shift"
x := 2r0100 >> 2. "divide by four"
x := 2r0100 << 2. "multiply by four"
x := 2r0100 bitAt: 3. "bit at position (0|1)"
x := 2r0100 highBit. "position of highest bit set"
b := 16rFF allMask: 16r0F. "test if all bits set in mask set in receiver"
b := 16rFF anyMask: 16r0F. "test if any bits set in mask set in receiver"
b := 16rFF noMask: 16r0F. "test if all bits set in mask clear in receiver"| x |
x := 3.99 asInteger. "convert number to integer (truncates)"
x := 3.99 asFraction. "convert number to fraction"
x := 3 asFloat. "convert number to float"
x := 65 asCharacter. "convert integer to character"
x := $A asciiValue. "convert character to integer"
x := 3.99 printString. "convert object to string via printOn:"
x := 3.99 storeString. "convert object to string via storeOn:"
x := 15 radix: 16. "convert to string in given base"
x := 15 printStringBase: 2. "string in given base"- blocks are objects and may be assigned to a variable
- a block value is last expression evaluated unless explicit return
- blocks may be nested
- syntax is [ :arguments | | localvars | expression . expression ]
- ^ expression terminates block & method (exits all nested blocks)
- blocks intended for long term storage should not contain ^
| x y z |
x := [ y := 1. z := 2. ]. x value. "simple block usage"
x := [ :argOne :argTwo | argOne, ' and ' , argTwo.]. "set up block with argument passing"
Transcript show: (x value: 'First' value: 'Second'); cr. "use block with argument passing"
x := [ | t | t := 1.]. "local var in block"- unary methods are messages with no arguments
- binary methods
- keyword methods are messages with selectors including colons
| x |
x := 2 sqrt. "unary message"
x := 2 raisedTo: 10. "keyword message"
x := 194 * 9. "binary message"
Transcript show: (194 * 9) printString; cr. "combination (chaining)"
x := 2 perform: #sqrt. "indirect method invocation"
Transcript "Cascading - send multiple messages to receiver"
show: 'hello ';
show: 'world';
cr.
x := 3 + 2; * 100. "result=300. Sends message to same receiver (3)"- follows the inheritance chain
- self send triggers a method lookup starting from the class of receiver
- super send triggers a method lookup starting from the superclass of the class containing the super expression!
Standard protocols:
- initialize (methods called for new instance)
- accessing (get/set methods)
- testing (boolean tests - is)
- comparing (boolean tests with parameter)
- displaying (gui related methods)
- printing (methods for printing)
- updating (receive notification of changes)
- private (methods private to class)
| x switch result |
X := 20 atRandom.
x > 10 ifTrue: [ 'ifTrue' traceCr ]. "if then"
x > 10 ifFalse: [ 'ifFalse' traceCr ]. "if else"
x > 10 "if then else"
ifTrue: [ 'ifTrue' traceCr ]
ifFalse: [ 'ifFalse' traceCr ].
x > 10 "if else then"
ifFalse: [Transcript show: 'ifFalse'; cr]
ifTrue: [Transcript show: 'ifTrue'; cr].
(x > 10
ifTrue: ['ifTrue']
ifFalse: ['ifFalse']) traceCr.switch := Dictionary new. "switch functionality"
switch at: $A put: [ 'Case A' traceCr].
switch at: $B put: [ 'Case B' traceCr].
switch at: $C put: [ 'Case C' traceCr].
result := (switch at: $B) value.| x y |
x := 4. y := 1.
[x > 0] whileTrue: [x := x - 1. y := y * 2]. "while true loop"
[x >= 4] whileFalse: [x := x + 1. y := y * 2]. "while false loop"
x timesRepeat: [y := y * 2]. "times repear loop (i := 1 to x)"
1 to: x do: [:a | y := y * 2]. "for loop"
1 to: x by: 2 do: [:a | y := y / 2]. "for loop with specified increment"
#(5 4 3) do: [:a | x := x + a]. "iterate over array elements"| b x y |
x := 'This is a string'. "string assignment"
x allButFirst: 10. "returns string"
x := 'String', 'Concatenation'. "string concatenation"
b := x isEmpty. "test if string is empty"
y := x size. "string size"
y := x at: 2. "char at location"
y := x copyFrom: 2 to: 4. "substring"
y := x indexOf: $a ifAbsent: [0]. "first position of character within string"
x := String with: $a with: $b with: $c with: $d. "set up to 4 elements at a time"
x do: [:a | Transcript show: a printString; cr]. "iterate over the string"
y := x select: [:a | a > $a]. "return all elements that meet condition"
y := x asSymbol. "convert string to symbol"
y := x asArray. "convert string to array"
x := 'ABCD' asByteArray. "convert string to byte array"
y := x asOrderedCollection. "convert string to ordered collection"
y := x asSortedCollection. "convert string to sorted collection"
y := x asBag. "convert string to bag collection"
y := x asSet. "convert string to set collection"
y := x shuffled. "randomly shuffle string"| x y |
x := $A. "character assignment"
y := x isLowercase. "test if lower case"
y := x isUppercase. "test if upper case"
y := x isLetter. "test if letter"
y := x isDigit. "test if digit"
y := x isAlphaNumeric. "test if alphanumeric"
y := x isSeparator. "test if seperator char"
y := x isVowel. "test if vowel"
y := x digitValue. "convert to numeric digit value"
y := x asLowercase. "convert to lower case"
y := x asUppercase. "convert to upper case"
y := x asciiValue. "convert to numeric ascii value"
y := x asString. "convert to string"
y := $A <= $B. "comparison"
y := $A max: $B.| b x y |
x := #Hello. "symbol assignment"
y := 'String', 'Concatenation'. "symbol concatenation (result is string)"
b := x isEmpty. "test if symbol is empty"
y := x size. "string size"
y := x at: 2. "char at location"
y := x copyFrom: 2 to: 4. "substring"
y := x indexOf: $e ifAbsent: [0]. "first position of character within string"
x do: [:a | Transcript show: a printString; cr]. "iterate over the string"
y := x select: [:a | a > $a]. "return all elements that meet condition"
y := x asString. "convert symbol to string"
y := x asText. "convert symbol to text"
y := x asArray. "convert symbol to array"
y := x asOrderedCollection. "convert symbol to ordered collection"
y := x asSortedCollection. "convert symbol to sorted collection"
y := x asBag. "convert symbol to bag collection"
y := x asSet. "convert symbol to set collection"- ByteArray: Array limited to byte elements (0-255)
- WordArray: Array limited to word elements (0-2^32)
| b x y sum max |
x := #[255 255 255]. "constant byte array"
x := #(4 3 2 1). "literal array"
x := #((1 + 2) . 3). "literal array whose first element is an array of size 3"
x := { 5. 2 * 2 + 1 . 3+2 . 8 - 3 }. "dynamic array"
x := Array with: 5 with: 4 with: 3 with: 2. "create array with up to 4 elements"
x := Array new: 4. "allocate an array with specified size"
x "set array elements"
at: 1 put: 5;
at: 2 put: 4;
at: 3 put: 3;
at: 4 put: 2.
b := x isEmpty. "test if array is empty"
y := x size. "array size"
y := x at: 4. "get array element at index"
b := x includes: 3. "test if element is in array"
y := x copyFrom: 2 to: 4. "subarray"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within array"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the array"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum array elements"
sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum array elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum array elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in array"
ifTrue: [a]
ifFalse: [c]].
y := x shuffled. "randomly shuffle collection"
y := x asArray. "convert to array"
y := x asByteArray. "convert to byte array"
y := x asWordArray. "convert to word array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"acts like an expandable array
| b x y sum max |
x := OrderedCollection with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements"
x := OrderedCollection new. "allocate collection"
x add: 3; add: 2; add: 1; add: 4; yourself. "add element to collection"
y := x addFirst: 5. "add element at beginning of collection"
y := x removeFirst. "remove first element in collection"
y := x addLast: 6. "add element at end of collection"
y := x removeLast. "remove last element in collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
x at: 2 put: 3. "set element at index"
y := x remove: 5 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: 2. "retrieve element at index"
y := x first. "retrieve first element in collection"
y := x last. "retrieve last element in collection"
b := x includes: 5. "test if element is in collection"
y := x copyFrom: 2 to: 3. "subcollection"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x shuffled. "randomly shuffle collection"
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"Like OrderedCollection except order of elements determined by sorting criteria
| b x y sum max |
x := SortedCollection with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements"
x := SortedCollection new. "allocate collection"
x := SortedCollection sortBlock: [:a :c | a > c]. "set sort criteria"
x add: 3; add: 2; add: 1; add: 4; yourself. "add element to collection"
y := x removeFirst. "remove first element in collection"
y := x addLast: 5. "add element at end of collection"
y := x removeLast. "remove last element in collection"
y := x addAll: #(6 7 8). "add multiple elements to collection"
y := x removeAll: #(6 7 8). "remove multiple elements from collection"
y := x remove: 5 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: 2. "retrieve element at index"
y := x first. "retrieve first element in collection"
y := x last. "retrieve last element in collection"
b := x includes: 4. "test if element is in collection"
y := x copyFrom: 2 to: 3. "subcollection"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"Like OrderedCollection except elements are in no particular order
| b x y sum max |
x := Bag with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements"
x := Bag new. "allocate collection"
x add: 4; add: 3; add: 1; add: 2; yourself. "add element to collection"
x add: 3 withOccurrences: 2. "add multiple copies to collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
y := x remove: 4 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
b := x includes: 3. "test if element is in collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"Like Bag except duplicates not allowed IdentitySet: uses identity test (== rather than =)
| b x y sum max |
x := Set with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements"
x := Set new. "allocate collection"
x add: 4; add: 3; add: 1; add: 2; yourself. "add element to collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
y := x remove: 4 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
x includes: 4. "test if element is in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"| b x y sum max |
x := Interval from: 5 to: 10. "create interval object"
x := 5 to: 10.
x := Interval from: 5 to: 10 by: 2. "create interval object with specified increment"
x := 5 to: 10 by: 2.
b := x isEmpty. "test if empty"
y := x size. "number of elements"
x includes: 9. "test if element is in collection"
x do: [:k | Transcript show: k printString; cr]. "iterate over interval"
y := x select: [:a | a > 7]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"| x y |
x := #myVar->'hello'.
y := x key.
y := x value.- IdentityDictionary: uses identity test (== rather than =)
| b x y |
x := Dictionary new. "allocate collection"
x add: #a->4; add: #b->3; add: #c->1; add: #d->2; yourself. "add element to collection"
x at: #e put: 3. "set element at index"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: #a ifAbsent: []. "retrieve element at index"
y := x keyAtValue: 3 ifAbsent: []. "retrieve key for given value with error block"
y := x removeKey: #e ifAbsent: []. "remove element from collection"
b := x includes: 3. "test if element is in values collection"
b := x includesKey: #a. "test if element is in keys collection"
y := x occurrencesOf: 3. "number of times object in collection"
y := x keys. "set of keys"
y := x values. "bag of values"
x do: [:a | Transcript show: a printString; cr]. "iterate over the values collection"
x keysDo: [:a | Transcript show: a printString; cr]. "iterate over the keys collection"
x associationsDo: [:a | Transcript show: a printString; cr]."iterate over the associations"
x keysAndValuesDo: [:aKey :aValue | Transcript "iterate over keys and values"
show: aKey printString; space;
show: aValue printString; cr].
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x detect: [:a | a > 3] ifNone: []. "return first element that passes test"
sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in collection"
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"| b x ios |
ios := ReadStream on: 'Hello read stream'.
ios := ReadStream on: 'Hello read stream' from: 1 to: 5.
[ (x := ios nextLine) notNil ]
whileTrue: [ x traceCr ].
ios position: 3.
ios position.
x := ios next.
x := ios peek.
x := ios contents.
b := ios atEnd.
ios := ReadWriteStream on: 'Hello read stream'.
ios := ReadWriteStream on: 'Hello read stream' from: 1 to: 5.
ios := ReadWriteStream with: 'Hello read stream'.
ios := ReadWriteStream with: 'Hello read stream' from: 1 to: 10.
ios position: 0.
[ (x := ios nextLine) notNil ]
whileTrue: [ x traceCr ].
ios position: 6.
ios position.
ios nextPutAll: 'Chris'.
x := ios next.
x := ios peek.
x := ios contents.
b := ios atEnd."Creating a file"
file := File named: 'asd.txt' asFileReference fullName.
"Opening / closing it"
file open.
file openForAppend.
file close.
"Accessing the file properties"
file size.
file position.
file position: 0.
file seekAbsolute: 10.
file seekRelative: 10.
file atEnd.
"Writing"
file nextPutAll: 'sdd'.
"Reading"
file next: 2.
"Buffered write"
file next: 2 putAll: 'abc' startingAt: 2.
"Buffered read"
buffer := ByteArray new: 5.
file readInto: buffer startingAt: 1 count: 5.
buffer asString.| p m hello |
p := FileLocator home. "user's home directory"
p := FileLocator root. "file system root"
p pathString. "file path string"
p parent pathString. "path of the parent folder"
m := FileLocator home / 'Music'. "handle to ~/Music"
m exists. "test if file/folder exists"
m isDirectory. "test if handle is a folder"
m allChildrenMatching: '.mp3'. "finding all mp3 files in folder"
p := 'pharo5.image' asFileReference. "handle to pharo.image file"
p isFile. "test if handle is a file"
p basename. "obtain filename without path"
hello := 'hello.txt' asFileReference.
hello writeStreamDo: [ :stream | "write to file"
stream nextPutAll: 'Hello World'].
hello readStreamDo: [ :stream | stream contents ]. "read from file"| x y |
x := Date today. "create date for today"
x := Date dateAndTimeNow. "create date from current time/date"
x := Date readFromString: '01/02/1999'. "create date from formatted string"
x := Date newDay: 12 month: #July year: 1999. "create date from parts"
x := Date fromDays: 36000. "create date from elapsed days since 1/1/1901"
y := Date dayOfWeek: #Monday. "day of week as int (1-7)"
y := Date indexOfMonth: #January. "month of year as int (1-12)"
y := Date daysInMonth: 2 forYear: 1996. "day of month as int (1-31)"
y := Date daysInYear: 1996. "days in year (365|366)"
y := Date nameOfDay: 1. "weekday name (#Monday,...)"
y := Date nameOfMonth: 1. "month name (#January,...)"
y := x weekday. "day of week (#Monday,...)"
y := x previous: #Monday. "date for previous day of week"
y := x dayOfMonth. "day of month (1-31)"
y := x day. "day of year (1-366)"
y := x firstDayOfMonth. "day of year for first day of month"
y := x monthName. "month of year (#January,...)"
y := x monthIndex. "month of year (1-12)"
y := x daysInMonth. "days in month (1-31)"
y := x year. "year (19xx)"
y := x daysInYear. "days in year (365|366)"
y := x daysLeftInYear. "days left in year (364|365)"
y := x asSeconds. "seconds elapsed since 1/1/1901"
y := x addDays: 10. "add days to date object"
y := x subtractDays: 10. "subtract days to date object"
y := x subtractDate: (Date today). "subtract date (result in days)"
y := x printFormat: #(2 1 3 $/ 1 1). "print formatted date"
b := (x <= Date today). "comparison"| x y |
x := Time now. "create time from current time"
x := Time now asdateAndTime. "create time from current time/date"
x := Time readFromString: '3:47:26 pm'. "create time from formatted string"
x := Time fromSeconds: 60 * 60 * 4. "create time from elapsed time from midnight"
y := Time millisecondClockValue. "milliseconds since midnight"
y := Time totalSeconds. "total seconds since 1/1/1901"
y := x seconds. "seconds past minute (0-59)"
y := x minutes. "minutes past hour (0-59)"
y := x hours. "hours past midnight (0-23)"
y := x addTime: Time now. "add time to time object"
y := x subtractTime: (Time now). "subtract time to time object"
y := x asSeconds. "convert time to seconds"
x := Time millisecondsToRun: [ "timing facility"
1 to: 1000 do: [:index | y := 3.14 * index]].
b := x <= Time now. "comparison"| pt x y |
pt := 200@100. "obtain a new point"
x := pt x. "x coordinate"
y := pt y. "y coordinate"
pt := 200@100 negated. "negates x and y"
pt := (-200@ -100) abs. "absolute value of x and y"
pt := (200.5@100.5) rounded. "round x and y"
pt := (200.5@100.5) truncated. "truncate x and y"
pt := 200@100 + 100. "add scale to both x and y"
pt := 200@100 - 100. "subtract scale from both x and y"
pt := 200@100 * 2. "multiply x and y by scale"
pt := 200@100 / 2. "divide x and y by scale"
pt := 200@100 // 2. "divide x and y by scale"
pt := 200@100 \\ 3. "remainder of x and y by scale"
pt := (200@100) + (50@25). "add points"
pt := (200@100) – (50@25). "subtract points"
pt := (200@100) * (3@4). "multiply points"
pt := (200@100) // (3@4). "divide points"
pt := 200@100 max: 50@200. "max x and y"
pt := 200@100 min: 50@200. "min x and y"
pt := 20@5 dotProduct: 10@2. "sum of product (x1*x2 + y1*y2)Rectangle fromUser.| receiver message result argument keyword1 keyword2 argument1 argument2 |
receiver := 5.
message := 'factorial' asSymbol.
result := receiver perform: message.
result := Compiler evaluate: ((receiver storeString), ' ', message).
result := (Message new setSelector: message arguments: #()) sentTo: receiver.receiver := 1.
message := '+' asSymbol.
argument := 2.
result := receiver perform: message withArguments: (Array with: argument).
result := Compiler evaluate: ((receiver storeString), ' ', message, ' ', (argument storeString)).
result := (Message new setSelector: message arguments: (Array with: argument)) sentTo: receiver.receiver := 12.
keyword1 := 'between:' asSymbol.
keyword2 := 'and:' asSymbol.
argument1 := 10.
argument2 := 20.
result := receiver
perform: (keyword1, keyword2) asSymbol
withArguments: (Array with: argument1 with: argument2).
result := Compiler evaluate:
((receiver storeString), ' ', keyword1, (argument1 storeString) , ' ', keyword2, (argument2 storeString)).
result := (Message new
setSelector: (keyword1, keyword2) asSymbol
arguments: (Array with: argument1 with: argument2))
sentTo: receiver.Installing an exception handler
[ 1/0 ] on: ZeroDivide do: [ :ex | ... ex ... ].Raising an exception
Warning signal: 'watch out!'.Always execute last block
[ 1/0 ] ensure: [ 'exception' trace].Execute last block only if fail or unwind
[ 1/0 ] ifCurtailed: [ Transcript show: 'exception' ]. String browse. "browse specified class"
x inspect. "open object inspector window"
x confirm: 'Is this correct?'.
x halt. "breakpoint to open debugger window"
x halt: 'Halt message'.
x notify: 'Notify text'.
x error: 'Error string'. "open up error window with title"
x doesNotUnderstand: #cmrMessage. "flag message is not handled"
x shouldNotImplement. "flag message should not be implemented"
x subclassResponsibility. "flag message as abstract"
x errorImproperStore. "flag an improper store into indexable object"
x errorNonIntegerIndex. "flag only integers should be used as index"
x errorSubscriptBounds. "flag subscript out of bounds"
x primitiveFailed. "system primitive failed"'Hello World' trace. "output string in internal log"Stdio stdout nextPutAll: 'Hello world' "output string in external log"| x |
'Hello World' asMorph openInWindow.
UIManager default message: 'Hello Pharo'. "display message"
x := UIManager default request: 'Enter value:'. "prompt user for input using a flexible UI dispatcher"
(ZnEasy getPng: 'http://pharo.org/web/files/pharo.png')
asMorph openInWindow. "get the Pharo logo"| b x |
x := String name. "class name"
x := String category. "organization category"
x := String comment. "class comment"
x := String kindOfSubclass. "subclass type - subclass: variableSubclass, etc"
x := String definition. "class definition"
x := String instVarNames. "immediate instance variable names"
x := String allInstVarNames. "accumulated instance variable names"
x := String classVarNames. "immediate class variable names"
x := String allClassVarNames. "accumulated class variable names"
x := String sharedPools. "immediate dictionaries used as shared pools"
x := String allSharedPools. "accumulated dictionaries used as shared pools"
x := String selectors. "message selectors for class"
x := String sourceCodeAt: #capitalized. "source code for specified method"
x := String allInstances. "collection of all instances of class"
x := String superclass. "immediate superclass"
x := String allSuperclasses. "accumulated superclasses"
x := String withAllSuperclasses. "receiver class and accumulated superclasses"
x := String subclasses. "immediate subclasses"
x := String allSubclasses. "accumulated subclasses"
x := String withAllSubclasses. "receiver class and accumulated subclasses"
b := String instSize. "number of named instance variables"
b := String isFixed. "true if no indexed instance variables"
b := String isVariable. "true if has indexed instance variables"
b := String isPointers. "true if index instance vars contain objects"
b := String isBits. "true if index instance vars contain bytes/words"
b := String isBytes. "true if index instance vars contain bytes"
b := String isWords. "true if index instance vars contain words"
Object withAllSubclasses size. "get total number of class entries"