Manchester | 26-ITP-Jan | Mehroz Munir | Sprint 1 | Coursework

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

@@ -3,4 +3,7 @@ let count = 0;
 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
+// Line 3 is adding 1 to count variable and then saving this new value to count variable
+// = sign is being used to assign the new value of count to the count variable

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

@@ -6,6 +6,6 @@ let lastName = "Johnson";
 // 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 = ``;
+initials = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -12,12 +12,14 @@
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
 const base = filePath.slice(lastSlashIndex + 1);
-console.log(`The base part of ${filePath} is ${base}`);
+console.log(`The base part of ${filePath} is: \n ${base}` + "\n");
 
 // 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(1, lastSlashIndex);
+console.log(`The dir part of ${filePath} is: \n ${dir}` + "\n");
+const ext = filePath.slice(filePath.lastIndexOf("."));
+console.log(`The ext part of ${filePath} is: \n ${ext}`);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -2,8 +2,20 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+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
+
+//num in the above code represents integer numbers from 1 to 100
+// random() method in Math class is used in the above code returns floating numbers between 0(inclusive) and 1(exclusive)
+/*and (maximum - minimum + 1) will give use the number that when multiplied by values between 
+0(inclusive) and 1(exclusive) we will get results from 0 to 99.99999999..... including any decimal values in between
+and the Math.floor is used to get rid of the decimal values and return only numbers; so our
+values will become 0 to 99 only numbers.
+And at the end part of the equation we are adding minimum value i.e. 1 which will result in
+assigning values from 1 to 100 in num; that's why we are getting only values from 1 to 100 in our num
+and every time we print the num in console.log() we can get any values between 1 to 100 depending on the radom value returned 
+by the Math.random() method.*/

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

@@ -1,2 +1,4 @@
-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?
+//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 can solve this by making the above statements as comments using //

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

@@ -1,4 +1,12 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+//const age = 33;
+//age = age + 1;
+
+/* the mistake in the above code is the use of const which we use only to save the constant values
+which we don't want to change in the future; therefore, in the above example we would declare age
+as a variable rather than constant to solve the issue.*/
+
+let age = 33;
 age = age + 1;
+console.log(age);

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

@@ -1,5 +1,10 @@
 // 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}`);
+//console.log(`I was born in ${cityOfBirth}`);
+//const cityOfBirth = "Bolton";
+
+//the above code is not working because you are printing or using the cityOfBirth constant before initializing it
+// it can be solved by declaring and initializing the constant before using it as shown below:
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,18 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+//const last4Digits = cardNumber.slice(-4);
 
 // 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
+
+//I predicted that the code is not working because the cardNumber is a constant value and cannot be changed
+// but actually we are not changing the value of cardNumber we are just slicing it which will be stored in a different variable
+//and the cardNumber value will remain the same
+//After running the code, I have realized that the code is not working because cardNumber is a number and the slice is a method in String class
+//so, in order to make it work, we need to change cardNumber to String before calling the slice method
+
+const last4Digits = (cardNumber + "").slice(-4);
+console.log("Last four digits of card are : " + last4Digits);

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

@@ -1,2 +1,9 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+//const 12HourClockTime = "20:53";
+//const 24hourClockTime = "08:53";
+
+const twelveHourClockTime = "20:53";
+const twentyFourhourClockTime = "08:53";
+
+/*in javascript and also many other programming languages, we can't start the name of an identifier
+//  with a number, therefore, I have changed that to text form*/
+

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

@@ -2,7 +2,9 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); //error line of code
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , "")); //fixed
+
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +14,33 @@ 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
+/* There are three function calls in this file as shown by the following lines from the code:
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+console.log(`The percentage change is ${percentageChange}`);
+
+replaceAll and log are the functions in the above lines */
 
 // 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?
+/* The error is coming from the following line inside the replaceAll method that accepts two parameters separated by comma
+but in our code there is no comma for the separation and that is the problem
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+we can fix this by simply adding the comma after first parameter value as follows:
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , "")); */
 
 // c) Identify all the lines that are variable reassignment statements
+/* The following two lines are the variable reassignment statements:
+carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); */
 
 // d) Identify all the lines that are variable declarations
+/* All the lines that are variable declarations are as follows:
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); //error line of code
+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?
+/* This code is replacing all the comma characters with an empty character inside the carPrice String and then converting that String  to a Number
+The purpose of doing this is because in the later part of code we are doing some Math calculations on this number 
+and, therefore, we can't use String, we need to remove the commas in the String and convert that String into a number*/

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

@@ -12,14 +12,24 @@ 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: 6
 
 // b) How many function calls are there?
+// Ans: 1
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
+/* Ans: In this expression the operator % is used which will return the remainder when we divide movieLength by 60
+        Specifically, in the above code it is used to get the remaining seconds which will be left over after
+        converting the movieLength i.e given in seconds into minutes. */
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+/* Ans: Here, we are taking out all the remainder or left over seconds from the movieLength seconds
+        and then dividing that value by 60 to get the length of movie in minutes. */
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+/* Ans: result represents the total length of movie in hours, minutes and seconds. The better name 
+        could be "lengthOfMovieInHMS" */
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Ans: Yes, this code will work with all number values of movieLength

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

@@ -1,20 +1,47 @@
+//initialises a string variable with the value "399p"
 const penceString = "399p";
 
+//creates a substring of penceString to remove the trailing or the last character p value and
+//assign the new value to "penceStringWithoutTrailingP"
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
-);
+);  //it will save 399 in penceStringWithoutTrailingP
+
+/* The method padStart is used when we want our string to have at least some length; 
+ in this case if the length of our string is less than 3, we are going to put "0"
+ in extra spaces
+ The reason for padding the pence number string to 3 size is because in the next step
+ we will create a substring by removing the last two values 
+ and that will give us the pounds number value and the remaining characters will be the
+ pence value. */
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); //it will not change our string because 399 already has three characters
 
-const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+/* Here we are trying to get the pounds value out of the total pence value 
+   Therefore we are creating a substring of paddedPenceNumberString to 
+   create a string that removes the last two numbers from paddedPenceNumberString
+   which are pence numbers. */
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
 
+
+/* Here, we are doing two things:
+   1. we are creating a substring of paddedPenceNumberString
+   to get the pence numbers only by returning the last two numbers.
+   2. We are using padEnd method to pad our result to two character values
+      and adding 0 at the end if the length of our substring is less than 2
+
+   Note: However, our paddedPenceNumberString length is always going to be at least 3
+      and the below substring is going to return us the last two characters which is pence value
+      So, I don't understand the use padEnd and in fact, I tried commenting it and tested the code
+      with different penceString values and the results are same.  */
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
-
+
+// in the below code we are printing the value starting with £ symbol of pounds and pence separated by "."   
 console.log(`£${pounds}.${pence}`);
 
 // This program takes a string representing a price in pence

Sprint-1/4-stretch-explore/chrome.md

@@ -11,8 +11,12 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+Ans: It creates an alert message on my tab with the text "Hello world!"
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+Ans: It creates a message box on my tab with the input `"What is your name?"` and there is an input field beneath it for answering this question.
+
 What is the return value of `prompt`?
+Mehroz

Sprint-1/4-stretch-explore/objects.md

@@ -5,12 +5,102 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+ƒ log() { [native code] }
 
 Now enter just `console` in the Console, what output do you get back?
+console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
+assert
+: 
+ƒ assert()
+clear
+: 
+ƒ clear()
+context
+: 
+ƒ context()
+count
+: 
+ƒ count()
+countReset
+: 
+ƒ countReset()
+createTask
+: 
+ƒ createTask()
+debug
+: 
+ƒ debug()
+dir
+: 
+ƒ dir()
+dirxml
+: 
+ƒ dirxml()
+error
+: 
+ƒ error()
+group
+: 
+ƒ group()
+groupCollapsed
+: 
+ƒ groupCollapsed()
+groupEnd
+: 
+ƒ groupEnd()
+info
+: 
+ƒ info()
+log
+: 
+ƒ log()
+memory
+: 
+MemoryInfo {totalJSHeapSize: 11200000, usedJSHeapSize: 10000000, jsHeapSizeLimit: 3760000000}
+profile
+: 
+ƒ profile()
+profileEnd
+: 
+ƒ profileEnd()
+table
+: 
+ƒ table()
+time
+: 
+ƒ time()
+timeEnd
+: 
+ƒ timeEnd()
+timeLog
+: 
+ƒ timeLog()
+timeStamp
+: 
+ƒ timeStamp()
+trace
+: 
+ƒ trace()
+warn
+: 
+ƒ warn()
+Symbol(Symbol.toStringTag)
+: 
+"console"
+[[Prototype]]
+: 
+Object
+
 
 Try also entering `typeof console`
+It is object
 
 Answer the following questions:
 
 What does `console` store?
+console is an object that does not store anything but it is used to call debugging
+methods such as log or assert or trace
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+it means that the console object is calling its methods log or assert using the dot "." operator
+