sprint1 solutions

Author: Ofonimeedak

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

@@ -4,3 +4,5 @@ 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 of the code assigns a value to the declared variable count.
+// The = sign is an assignment operator, without line 3, the declared variable wil be undefined.

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

@@ -5,7 +5,6 @@ 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}+${lastName}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -17,7 +17,7 @@ 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,filePath.length-base.length-1) ;
+const ext = filePath.slice(-3);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,12 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // 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
+
+// In the above expression num represent a variable that will store the result of that will be obtained from from the expression.
+// maximum and minimum are variables available on the global scope, as inputs.
+// They are evaluated first because of the parenthesis, this gives the precedence
+// The output from the parenthesis is now going to serve as the range for the Math.random() method.
+// Math.random() method produce random values from 0-1, with 0 and 1 inclusive and exclusive respectively
+// The range value makes Math.random() to return result from 0 to  range-1
+//the Math.floor() methods rounds down the value to the nearest whole number.
+// The result from th random operation is added back to the minimum value to return num.

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

@@ -1,2 +1,2 @@
-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?

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

@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;

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

@@ -1,5 +1,8 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
-// what's the error ?
+ 
+// JavaScript is single-threaded because it executes tasks in a single flow using a call stack. The function was called before it was declared, 
+// It was also declared with const, which can not be hoisted to the top, like var.
+// this result to undefined.
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,4 +1,5 @@
-const cardNumber = 4533787178994213;
+let cardNumber = 4533787178994213;
+cardNumber=cardNumber.toString();
 const last4Digits = cardNumber.slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
@@ -7,3 +8,7 @@ const last4Digits = cardNumber.slice(-4);
 // 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
+
+// The variable cardNumber is a number data type, numbers do not have slice methods or function, only string does.
+//TypeError: cardNumber.slice is not a function
+// Yes, it gives what i predicted

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "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;
@@ -13,10 +13,21 @@ console.log(`The percentage change is ${percentageChange}`);
 
 // 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 call in this code.
+// 1. Line 4 has 2 function call, .replaceAll() and Number()
+//2. Line 5 ditto line 4
+// 3. line 10 console.log() that logs the result to the console
+
 // 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 in this code is coming from line 5. The wrong use of the replaceAll syntax without a separator.
+// I will fix this problem by reading the documentation, to see the right way the syntax should be written.
+//Then i will add the comma where necessary
 
 // c) Identify all the lines that are variable reassignment statements
+ // line 4 and 5 are variable reassignment
 
 // d) Identify all the lines that are variable declarations
+ // line 1,2,7,8 are all variable declaration
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// this expression replaces the comma at the string with an empty string and the convert the string data type to a number data type