fix 3.js task under mandatory -error and also fix percentage -change .js based on the comment given.

Author: Dagim-Daniel

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

@@ -1,15 +1,15 @@
-const cardNumber = "4533787178994213";
-const last4Digits = cardNumber.slice(-4);
-    console.log(last4Digits);
+const cardNumber = 4533787178994213;
+const last4Digits = String(cardNumber).slice(-4);
+console.log(last4Digits);
 // 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
-    // i predict that the code doesn't work its because of two things, first i thought its case sensitive things 
-    // the second one is the type of variable, i thought the slice method is only for string type variable.
+// i predict that the code doesn't work its because of two things, first i thought its case sensitive things
+// the second one is the type of variable, i thought the slice method is only for string type variable.
 
 // 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?
-        /*
+/*
     I run the code and it gives me an error that says "TypeError: cardNumber.slice is not a function".
     so i checked the type of cardNumber using typeof operator and it returns number.
     */

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;
@@ -12,27 +12,27 @@ 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 in this file. including methods used , 2 methods  = replaceAll(), methods are called under their object, replaceAll() is called under the string object.
-    // The lines where a function call is made are:
-    // Line 4: carPrice.replaceAll(",", "")
-    // Line 5: priceAfterOneYear.replaceAll(",", "")
-    // Line 7: console.log(`The percentage change is ${percentageChange}`)
+// there are 5 function calls in this file. including methods used , 2 methods  = replaceAll(), methods are called under their object, replaceAll() is called under the string object.
+// The lines where a function call is made are:
+// Line 4: carPrice.replaceAll(",", "")
+// Line 5: priceAfterOneYear.replaceAll(",", "")
+// Line 7: 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?
-    //syntaxError: missing ) after argument list, - 
-    //the error is occurring because of a missing "," in the replaceAll() method. in line 5.
+//syntaxError: missing ) after argument list, -
+//the error is occurring because of a missing "," between arguments in the replaceAll() method. in line 5.
 
 // c) Identify all the lines that are variable reassignment statements
-    // The lines that are variable reassignment statements are:
-    // Line 4: carPrice = Number(carPrice.replaceAll(",", ""));
-    // Line 5: priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+// The lines that are variable reassignment statements are:
+// Line 4: carPrice = Number(carPrice.replaceAll(",", ""));
+// Line 5: priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
 
 // d) Identify all the lines that are variable declarations
-    // The lines that are variable declarations are:
-    // Line 1: let carPrice = "10,000";
-    // Line 2: let priceAfterOneYear = "8,543";
-    // Line 7: const priceDifference = carPrice - priceAfterOneYear;
-    // Line 8: const percentageChange = (priceDifference / carPrice) * 100;
+// The lines that are variable declarations are:
+// Line 1: let carPrice = "10,000";
+// Line 2: let priceAfterOneYear = "8,543";
+// Line 7: const priceDifference = carPrice - priceAfterOneYear;
+// Line 8: const percentageChange = (priceDifference / carPrice) * 100;
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
-    // The expression Number(carPrice.replaceAll(",","")) is converting the string value of carPrice into a number by removing the comma from the string.
+// The expression Number(carPrice.replaceAll(",","")) is converting the string value of carPrice into a number by removing the comma from the string.