predicted and explained the error. and finally, fixed the code.

Author: ahmadehsas

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

@@ -9,5 +9,10 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// =============> write your explanation here: when i call the function capitalise with a string input, it shows an error because i am trying to redeclare the variable "str" inside the function, which is already defined as a parameter. this causes a syntax error and we can not redeclare a variable with the same name.
+// =============> write your new code here:  we can not use let str because str is  already the function parameter.
+
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}

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

@@ -1,7 +1,7 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============> write your prediction here: my prediction: The error will occur because i am  trying to redeclare the variable "decimalNumber".//
 
 // Try playing computer with the example to work out what is going on
 
@@ -14,7 +14,12 @@ function convertToPercentage(decimalNumber) {
 
 console.log(decimalNumber);
 
-// =============> write your explanation here
+// =============> write your explanation here: // the error: identifier `decimalNumber` has already been declared. this error shows that identifier has already been declared and we can not redeclare it again.The identifier `decimalNumber` declared in parameter.//
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+// function convertTopercentage(decimalNumber) {
+// const percentage = `${decimalNumber * 100}%`;
+// return percentage;
+// }
+// console.log(convertTopercentge(0.5));//