Key-errors tasks are done

Author: shaghayeghfar

Module-Structuring-and-Testing-Data.test.js

@@ -1,5 +1,5 @@
 // trying to create an age variable and then reassign the value by 1
 
-let age =33;
+let age = 33;
 age = age + 1;
-console.log(age);
+console.log(age);

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

@@ -1,5 +1,7 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> Prediction:
+// Calling capitalise("hello") will cause an error:
+// "Identifier 'str' has already been declared"
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -9,5 +11,15 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// =============> Explanation:
+// The error happens because 'str' is already a parameter.
+// We cannot declare another variable with the same name inside the function.
+
+// =============> Corrected Code:
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+
+// Example
+console.log(capitalise("hello")); // Output: "Hello"

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

@@ -1,20 +1,29 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
-
-// Try playing computer with the example to work out what is going on
+// =============> Prediction:
+// There will be an error because 'decimalNumber' is declared twice inside the function
+// and console.log(decimalNumber) outside the function will not work.
 
+// Original code:
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
+  const decimalNumber = 0.5; //  cannot declare again
   const percentage = `${decimalNumber * 100}%`;
-
   return percentage;
 }
 
-console.log(decimalNumber);
+console.log(decimalNumber); //  not defined
+
+// =============> Explanation:
+// 1. The function already has a parameter called 'decimalNumber', so using 'const decimalNumber' again is not allowed.
+// 2. The variable 'decimalNumber' only exists inside the function.
+//    You cannot use it outside the function.
 
-// =============> write your explanation here
+// =============> Corrected Code:
+function convertToPercentage(decimalNumber) {
+  const percentage = decimalNumber * 100 + "%"; // calculate percentage
+  return percentage;
+}
 
-// Finally, correct the code to fix the problem
-// =============> write your new code here
+// Example
+console.log(convertToPercentage(0.5)); // Output: "50%"

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

@@ -3,18 +3,26 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// =============> Prediction of the error:
+// The function will give an error because '3' is not a valid variable name. 
+// Function parameters must have names, not numbers.
 
 function square(3) {
     return num * num;
 }
 
-// =============> write the error message here
+// =============> Error message:
+// SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// =============> Explanation of the error:
+// 1. You cannot use a number as a parameter name. 
+// 2. Also, 'num' is not defined inside the function, so it will cause another error if we fix the parameter first.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// =============> Corrected Code:
+function square(num) {
+    return num
+}