ITP_JAN-2015|sabita-Shrestha|Module-Structuring-and-Testing-Data|week5|sprint1

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,20 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// In this code variable is declare as count = 0,  expression increments the value of count by 1 and variable count is updated to be count + 1.
+
+
+//An expression is any valid unit of code that have value. In this code , we have different types of expressions:
+// Assignment, arithmetic and compound assignment.
+// An operand is a value or variable that an operator acts upon in an expression.
+
+//count = 0	(Assignment	count) 
+//count + 1	(Arithmetic	count) 
+//count = count + 1	(Compound Assignment)
+
+// count 0 =
+//count 1 =
+// count + 1 = (this is operand) all this (=, + and = are operator)
+// So in this code count = 0 is an assignment expression because it assigns a value (0) to the variable count.
+//The = operator is the assignment operator.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,9 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+//text.charAt(0) means it will return first letter, if  we put 1 than it will return second letter.

Sprint-1/1-key-exercises/3-paths.js

@@ -4,7 +4,7 @@
 // │          dir        │    base    │
 // ├──────┬              ├──────┬─────┤
 // │ root │              │ name │ ext │
-// "  /    home/user/dir / file  .txt "
+//   /    home/user/dir / file  .txt 
 // └──────┴──────────────┴──────┴─────┘
 
 // (All spaces in the "" line should be ignored. They are purely for formatting.)
@@ -17,7 +17,11 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+console.log(`The dr part of ${filePath} is ${dir}`);
+const lastDotIndex = base.lastIndexOf(".");
+const ext = base.slice(lastDotIndex);
+console.log(`The ext part of ${filePath} is ${ext}`);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn
+//Using like lastIndex, lastSlashIndex, slice and LastDotIndex help to separate full file to other components in javascript.

Sprint-1/1-key-exercises/4-random.js

@@ -2,8 +2,51 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+console.log(num);
+console.log(num);
+
+
 
 // In this exercise, you will need to work out what num represents?
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+/*Assignment Expressions:
+minimum = 1
+maximum = 100
+const num = ...
+
+Function Call Expressions:
+Math.random()
+Math.floor(...)
+console.log(num)
+
+Arithmetic Expressions:
+(maximum - minimum + 1) (subtraction and addition)
+Math.random() * (maximum - minimum + 1) (multiplication)
+Math.floor(...) + minimum (addition)
+
+
+When you log several time it will so different value.
+ Math.random gives u the value if decimal number is higher than 0.5 than the output will round up or less than 0.5 will rounds down. for example: 5.95 will be 6, 5.34 output will be 5 and -4.6 will be -5.
+
+In the other hand Math.floor() function rounds a number down to the nearest integer, always moving towards negative infinity.
+for example: 5.95 will be 5 and -4.1 output will be -5.
+
+What is the significance of (maximum - minimum + 1)? What does this expression represent?
+This expression represents (maximum - minimum + 1) is used to adjust the range of values generated by the random number, ensuring that the range is inclusive of both the minimum and maximum values.
+Math.random() * (100 - 1 + 1) Generates a value between 0 and 100 (exclusive)
+Math.floor(Math.random() * (100 - 1 + 1)) Generates a value between 0 and 99 (inclusive)
+to get maximum we use +1.
+
+What is the significance of ... + minimum?
+The ... + minimum part of the expression is crucial because it shifts the generated random number to ensure that the range starts at the minimum value rather than at 0.
+Math.floor(Math.random() * (100 - 1 + 1)) + 1 it will be from 1 to 100 and without Math.floor(Math.random() * (100 - 1 + 1)) will be 0 to 99.
+
+What is the range of values that could be assigned to num?
+The value will be range between 1 to 100.
+
+To test your understanding, how would you write an expression (without using any variable in the expression) that can yield a random integer between -5 and 5 (including both -5 and 5)?
+Math.floor(Math.random() * 11) - 5
+To generate a random integer between -5 and 5 (inclusive), we need 11 possible integer values. */

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,3 @@
 This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+// Buy using comments syntax which is 2 slash 

Sprint-1/2-mandatory-errors/1.js

@@ -1,4 +1,6 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+console.log(age);
+// I have change const to let, It won't let you to reassign, it will say error if we use const.

Sprint-1/2-mandatory-errors/2.js

@@ -1,5 +1,7 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
+
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+// variable should declare before console.log.

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,16 @@
-const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
-
+const cardNumber = 4533787178994213;   
+const last4Digits = String(cardNumber).slice(-4); // convert to string and extract last 4 digit
+console.log(last4Digits); //print4213
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+//IN line 1  their was't  any string that may be the reason.
+//With out changing code its says TypeError
+
+/* how would you modify the code (through type conversion) so that it can still extract the last 4 digits from its value.
+To use slice() method we need to use string.
+

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";
+console.log(twelveHourClockTime);
+console.log(twentyFourHourClockTime);
+//it says syntax error because variable should start with letter or underscore.

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",",""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,24 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+//ans- There are 5 function calls:
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+//console.log(`The percentage change is ${percentageChange}`);
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// ans: It was SyntaxError: missing ) which is replaceAll(",", "")comma separate argument. 
 
 // c) Identify all the lines that are variable reassignment statements
+// ans: carPrice = Number(carPrice.replaceAll(",", "")); 
+//   priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",",""));
 
 // d) Identify all the lines that are variable declarations
+// ans: let carPrice = "10,000";
+//      let priceAfterOneYear = "8,543";
+//      const priceDifference = carPrice - priceAfterOneYear;
+//      const percentageChange = (priceDifference / carPrice) * 100;
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// ans: The expression Number(carPrice.replaceAll(",", "")) is used to convert a formatted string representation of a number (with commas) into an actual numeric value.
+//Basically Number(carPrice.replaceAll(",","")) remove comma, convert strings in to number. 

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -5,21 +5,39 @@ const totalMinutes = (movieLength - remainingSeconds) / 60;
 
 const remainingMinutes = totalMinutes % 60;
 const totalHours = (totalMinutes - remainingMinutes) / 60;
-
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 console.log(result);
 
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+//  ans:There are 6 variable declaration which are const.
 
 // b) How many function calls are there?
+//ans: There is only 1 function call which is console.log().
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+//ans: This is called remainder operator which divide the length of movie 8784 by 60 and place the remaining second which is 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// ans: It means movie length subtract the remaining seconds and use remainder operator like (8784-24=8760/60) which 146.
+// Also, this line interpret the expression calculates total number of complete minutes in movieLength (which is in seconds).
+//movieLength-remainingSecond
+// remainingSEcond = movieLength % 60
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// anns: Better name for this variable will be "formattedMovieDuration" because it is more descriptive, clearly indicating that the value is a formatted string representing the movie's duration.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+const movieLength = 2080; // length of movie in seconds
+
+const remainingSeconds = movieLength % 60;
+const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+const remainingMinutes = totalMinutes % 60;
+const totalHours = (totalMinutes - remainingMinutes) / 60;
+const timeString = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
+console.log(timeString);
+// It does work with another value as i change the movie length, it does work.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -20,8 +20,27 @@ console.log(`£${pounds}.${pence}`);
 // This program takes a string representing a price in pence
 // The program then builds up a string representing the price in pounds
 
-// You need to do a step-by-step breakdown of each line in this program
-// Try and describe the purpose / rationale behind each step
+// with the value "399p"You need to do a step-by-step breakdown of each line in this program
+// Try and describe the purpose / rationale behind each stepconst penceString = "399p";
 
 // To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 1. const penceString = "399p": initializes a string variable 
+// this one initializes the penceString value with of 399 in pence.
+
+//const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);
+ //In this line,the last character of penceString variable will be remove and converts price string like "399p" will be 399.
+// 
+
+//const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+//This line make sure the string "penceStringWithoutTrailingP" has 3 character and also adding "0" if necessary and it also penceStringWithoutTrailingP is "99" also padded to "099".
+
+//const pounds = paddedPenceNumberString.substring(0,  paddedPenceNumberString.length - 2);
+//This line remove the part of the string which is pound and substring from the start(0) to characters before the end paddedPenceNumberString.   
+
+//const pence = paddedPenceNumberString .substring(paddedPenceNumberString.length - 2) .padEnd(2, "0");
+//This line of code extracts 2 characters of the string "paddedPenceNumberString" also pads the results to make sure it has 2 characters by adding 0 to format properly.
+//Calculate the starting index of the last two characters of 399 (length - 2) input will be 99.
+// It also Extract everything from that point to the end of the string using substring().
+
+//console.log(`£${pounds}.${pence}`);
+// It will print price in pound and pence in format. which will print 3.99