Manchester | 25-ITP-May | Fithi Teklom| Sprint 1 | Coursework Sprint 1

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

@@ -3,4 +3,4 @@ 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
+// So line 3 is adding the value of the variable we created which is count and assigned it as zero by 1. Or we are updating count to be one more than it was before.

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[0] + middleName[0] + lastName[0]}`;
+
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -3,7 +3,12 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
-// 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
+console.log(num);
+
+// num is a random integer between minimum and maximum, including both endpoints.
+// Math.random generates random decimal numbers between 0 and 1.
+// Math.floor() rounds a number down to the nearest integer.Example 12.8 is rounded to 12.
+//(maximum - minimum + 1)= (100 - 1 + 1)= 100.... So the expression becomes (Math.random()*100)
+//In the output I can see random numbers between 1 and 100.
+
+

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?
+//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 simply comment it out by adding two slashes(//) at the begining of line 1 and line 2.

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;
+//let allows the variable to be reassigned later.
+//const is only for values that should never change.

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}`);
+
+//declaration and initialization comes first always.

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

@@ -1,9 +1,8 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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
+console.log(last4Digits);
+
+//I predicted the error which is type error. cardNumber is a number not a string.
+//.slice() only works on strings (or arrays).
+//Numbers in JavaScript do not have a slice method.

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const Hour12ClockTime = "20:53";
+const hour24ClockTime = "08:53";

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 +12,20 @@ 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 5 function calls. Number(), carPrice.replaceAll(),priceAfterOneYear.replaceAll(), console.log(),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?
+//The error is at line 5. It is a Syntax error. A comma is expected in between the two strings.By adding , in between the stings.
 
 // c) Identify all the lines that are variable reassignment statements
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ,""));
 
 // d) Identify all the lines that are variable declarations
+//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?
+// It replaces the number to a clean string.

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

@@ -12,14 +12,21 @@ 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?
+// There are 6.
 
 // b) How many function calls are there?
+//1 function call.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+//Remainder assignment. Which means when 8784 seconds is divided by 60 it gives 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+//movieLength - remainingSeconds removes the leftover seconds that don’t make up a full minute.
+//Dividing that by 60 converts the remaining seconds into whole minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+//It represents movie duration. A better name can be formattedMovie.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Mostly yes, but not good for fractional values, negative numbers and numbers less than 0, the leading 0 may not be displayed.