Adding more

nilaydatta · nilaydatta · commit 81d6633c7f5b · 2020-02-23T23:09:34.000+05:30
diff --git a/array-methods.js b/array-methods.js
@@ -26,6 +26,8 @@ x.sort(function(a, b){return b - a});   // numeric descending sort
 highest = x[0];                         // first item in sorted array is the lowest (or highest) value
 x.sort(function(a, b){return 0.5 - Math.random()});     // random order sort
 
+concat, copyWithin, every, fill, filter, find, findIndex, forEach, indexOf, isArray, join, lastIndexOf, map, pop, push, reduce, reduceRight, reverse, shift, slice, some, sort, splice, toString, unshift, valueOf
+
 /* More Array Methods */
 
 // Accessing Elements I
diff --git a/break-continue.js b/break-continue.js
@@ -0,0 +1,12 @@
+for (var i = 0; i < 10; i++) {
+  if (i == 5) {
+    break; // stops and exits the cycle
+  }
+  document.write(i + ", "); // last output number is 4
+}
+for (var i = 0; i < 10; i++) {
+  if (i == 5) {
+    continue; // skips the rest of the cycle
+  }
+  document.write(i + ", "); // skips 5
+}
diff --git a/comments.js b/comments.js
@@ -0,0 +1,3 @@
+/* Multi line
+   comment */
+// One line
diff --git a/do-while-loop.js b/do-while-loop.js
@@ -0,0 +1,6 @@
+var i = 1; // initialize
+do {
+  // enters cycle at least once
+  i *= 2; // increment to avoid infinite loop
+  document.write(i + ", "); // output
+} while (i < 100); // repeats cycle if statement is true at the end
diff --git a/error-try-catch-throw.js b/error-try-catch-throw.js
@@ -0,0 +1,27 @@
+try {
+  // block of code to try
+  undefinedFunction();
+} catch (err) {
+  // block to handle errors
+  console.log(err.message);
+}
+
+// Throw error
+
+throw "My error message"; // throw a text
+
+// Input validation
+
+var x = document.getElementById("mynum").value; // get input value
+try {
+  if (x == "") throw "empty"; // error cases
+  if (isNaN(x)) throw "not a number";
+  x = Number(x);
+  if (x > 10) throw "too high";
+} catch (err) {
+  // if there's an error
+  document.write("Input is " + err); // output error
+  console.error(err); // write the error in console
+} finally {
+  document.write("</br />Done"); // executed regardless of the try / catch result
+}
diff --git a/error-types.js b/error-types.js
@@ -0,0 +1,6 @@
+// Error name values
+RangeError        A number is "out of range"
+ReferenceError    An illegal reference has occurred
+SyntaxError       A syntax error has occurred
+TypeError         A type error has occurred
+URIError          An encodeURI() error has occurred
diff --git a/for-loops.js b/for-loops.js
@@ -0,0 +1,11 @@
+for (var i = 0; i < 10; i++) {
+  document.write(i + ": " + i*3 + "<br />");
+}
+var sum = 0;
+for (var i = 0; i < a.length; i++) {
+  sum + = a[i];
+}               // parsing an array
+html = "";
+for (var i of custOrder) {
+  html += "<li>" + i + "</li>";
+}
diff --git a/functions.js b/functions.js
@@ -0,0 +1,4 @@
+function addNumbers(a, b) {
+  return a + b;
+}
+x = addNumbers(1, 2);
diff --git a/js-date-object.js b/js-date-object.js
@@ -0,0 +1,40 @@
+// Sat Feb 22 2020 19:31:24 GMT+0530 (India Standard Time)
+var d = new Date();
+
+// 1582380084791 miliseconds passed since 1970
+
+Number(d);
+Date("2017-06-23"); // date declaration
+Date("2017"); // is set to Jan 01
+Date("2017-06-23T12:00:00-09:45"); // date - time YYYY-MM-DDTHH:MM:SSZ
+Date("June 23 2017"); // long date format
+Date("Jun 23 2017 07:45:00 GMT+0100 (Tokyo Time)"); // time zone
+
+// Get Times
+
+var d = new Date();
+a = d.getDay(); // getting the weekday
+
+getDate(); // day as a number (1-31)
+getDay(); // weekday as a number (0-6)
+getFullYear(); // four digit year (yyyy)
+getHours(); // hour (0-23)
+getMilliseconds(); // milliseconds (0-999)
+getMinutes(); // minutes (0-59)
+getMonth(); // month (0-11)
+getSeconds(); // seconds (0-59)
+getTime(); // milliseconds since 1970
+
+// Setting part of a date
+
+var d = new Date();
+d.setDate(d.getDate() + 7); // adds a week to a date
+
+setDate(); // day as a number (1-31)
+setFullYear(); // year (optionally month and day)
+setHours(); // hour (0-23)
+setMilliseconds(); // milliseconds (0-999)
+setMinutes(); // minutes (0-59)
+setMonth(); // month (0-11)
+setSeconds(); // seconds (0-59)
+setTime(); // milliseconds since 1970)
diff --git a/js-global-functions.js b/js-global-functions.js
@@ -0,0 +1,12 @@
+eval(); // executes a string as if it was script code
+String(23); // return string from number
+(23).toString(); // return string from number
+Number("23"); // return number from string
+decodeURI(enc); // decode URI. Result: "my page.asp"
+encodeURI(uri); // encode URI. Result: "my%page.asp"
+decodeURIComponent(enc); // decode a URI component
+encodeURIComponent(uri); // encode a URI component
+isFinite(); // is variable a finite, legal number
+isNaN(); // is variable an illegal number
+parseFloat(); // returns floating point number of string
+parseInt(); // parses a string and returns an integer
diff --git a/js-math-object.js b/js-math-object.js
@@ -0,0 +1,19 @@
+var pi = Math.PI; // 3.141592653589793
+Math.round(4.4); // = 4 - rounded
+Math.round(4.5); // = 5
+Math.pow(2, 8); // = 256 - 2 to the power of 8
+Math.sqrt(49); // = 7 - square root
+Math.abs(-3.14); // = 3.14 - absolute, positive value
+Math.ceil(3.14); // = 4 - rounded up
+Math.floor(3.99); // = 3 - rounded down
+Math.sin(0); // = 0 - sine
+Math.cos(Math.PI); // OTHERS: tan,atan,asin,acos,
+Math.min(0, 3, -2, 2); // = -2 - the lowest value
+Math.max(0, 3, -2, 2); // = 3 - the highest value
+Math.log(1); // = 0 natural logarithm
+Math.exp(1); // = 2.7182pow(E,x)
+Math.random(); // random number between 0 and 1
+Math.floor(Math.random() * 5) + 1; // random integer, from 1 to 5
+
+// Constants like Math.PI:
+E, PI, SQRT2, SQRT1_2, LN2, LN10, LOG2E, Log10E;
diff --git a/js-promises.js b/js-promises.js
@@ -0,0 +1,40 @@
+function sum(a, b) {
+  return Promise(function(resolve, reject) {
+    setTimeout(function() {
+      // send the response after 1 second
+      if (typeof a !== "number" || typeof b !== "number") {
+        // testing input types
+        return reject(new TypeError("Inputs must be numbers"));
+      }
+      resolve(a + b);
+    }, 1000);
+  });
+}
+var myPromise = sum(10, 5);
+myPromsise
+  .then(function(result) {
+    document.write(" 10 + 5: ", result);
+    return sum(null, "foo"); // Invalid data and return another promise
+  })
+  .then(function() {
+    // Won't be called because of the error
+  })
+  .catch(function(err) {
+    // The catch handler is called instead, after another second
+    console.error(err); // => Please provide two numbers to sum.
+  });
+
+// States
+
+pending, fulfilled, rejected;
+
+// Properties
+
+Promise.length, Promise.prototype;
+
+// Methods
+
+Promise.all(iterable),
+  Promise.race(iterable),
+  Promise.reject(reason),
+  Promise.resolve(value);
diff --git a/json-methos.js b/json-methos.js
@@ -0,0 +1,22 @@
+var str =
+  '{"names":[' + // crate JSON object
+  '{"first":"Hakuna","lastN":"Matata" },' +
+  '{"first":"Jane","lastN":"Doe" },' +
+  '{"first":"Air","last":"Jordan" }]}';
+obj = JSON.parse(str); // parse
+document.write(obj.names[1].first); // access
+
+// Send
+
+var myObj = { name: "Jane", age: 18, city: "Chicago" }; // create object
+var myJSON = JSON.stringify(myObj); // stringify
+window.location = "demo.php?x=" + myJSON; // send to php
+
+// Storing and retrieving
+
+myObj = { name: "Jane", age: 18, city: "Chicago" };
+myJSON = JSON.stringify(myObj); // storing data
+localStorage.setItem("testJSON", myJSON);
+text = localStorage.getItem("testJSON"); // retrieving data
+obj = JSON.parse(text);
+document.write(obj.name);
diff --git a/numbers.js b/numbers.js
@@ -0,0 +1,13 @@
+var pi = 3.141;
+pi.toFixed(0); // returns 3
+pi.toFixed(2); // returns 3.14 - for working with money
+pi.toPrecision(2); // returns 3.1
+pi.valueOf(); // returns number
+Number(true); // converts to number
+Number(new Date()); // number of milliseconds since 1970
+parseInt("3 months"); // returns the first number: 3
+parseFloat("3.5 days"); // returns 3.5
+Number.MAX_VALUE; // largest possible JS number
+Number.MIN_VALUE; // smallest possible JS number
+Number.NEGATIVE_INFINITY; // -Infinity
+Number.POSITIVE_INFINITY; // Infinity
diff --git a/object-methods.js b/object-methods.js
@@ -0,0 +1,14 @@
+var student = {
+  // object name
+  firstName: "Jane", // list of properties and values
+  lastName: "Doe",
+  age: 18,
+  height: 170,
+  fullName: function() {
+    // object function
+    return this.firstName + " " + this.lastName;
+  }
+};
+student.age = 19; // setting value
+student[age]++; // incrementing
+name = student.fullName(); // call object function
diff --git a/operators.js b/operators.js
@@ -0,0 +1,14 @@
+a = b + c - d; // addition, substraction
+a = b * (c / d); // multiplication, division
+x = 100 % 48; // modulo. 100 / 48 remainder = 4
+a++;
+b--; // postfix increment and decrement
+
+// Bitwise operators
+&	AND 	 5 & 1 (0101 & 0001)	1 (1)
+|	OR 	 5 | 1 (0101 | 0001)	5 (101)
+~	NOT 	 ~ 5 (~0101)	10 (1010)
+^	XOR 	 5 ^ 1 (0101 ^ 0001)	4 (100)
+<<	left shift 	 5 << 1 (0101 << 1)	10 (1010)
+>>	right shift 	 5 >> 1 (0101 >> 1)	2 (10)
+>>>	zero fill right shift 	 5 >>> 1 (0101 >>> 1)	2 (10)
diff --git a/regular-expressions.js b/regular-expressions.js
@@ -0,0 +1,21 @@
+var a = str.search(/CheatSheet/i);
+
+// Modifiers
+
+i       perform case-insensitive matching
+g       perform a global match
+m       perform multiline matching
+
+// Patterns
+
+\       Escape character
+\d      find a digit
+\s      find a whitespace character
+\b      find match at beginning or end of a word
+n+      contains at least one n
+n*      contains zero or more occurrences of n
+n?      contains zero or one occurrences of n
+^       Start of string
+$       End of string
+\uxxxx  find the Unicode character
+.       Any single character
diff --git a/strict.js b/strict.js
@@ -0,0 +1,2 @@
+"use strict"; // Use strict mode to write secure code
+x = 1; // Throws an error because variable is not declared
diff --git a/while-loops.js b/while-loops.js
@@ -0,0 +1,6 @@
+var i = 1; // initialize
+while (i < 100) {
+  // enters the cycle if statement is true
+  i *= 2; // increment to avoid infinite loop
+  document.write(i + ", "); // output
+}

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+/* Multi line`
	`2`	`+ comment */`
	`3`	`+// One line`