Fix variable redeclaration error in convertToPercentage function

Author: HadiVahidi20

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

@@ -2,19 +2,36 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
-
+// the problem is in line 10, because we can not use the "decimalNumber" twice, currently once we used as parameter and again as variable,
+// this will cause an error "SyntaxError: Identifier 'decimalNumber' has already been declared"
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-  return percentage;
-}
+//   return percentage;
+// }
 
-console.log(decimalNumber);
+// console.log(decimalNumber);
 
 // =============> write your explanation here
-
+// by line 9 the computer we remember the name of the function and its parameter but still it doesn't do any thing.
+// by line 10 the computer will try to declare a new variable with the same name as the parameter of the function 
+// and it will cause an error because we can not use the same name twice in the same scope. even if it accept it no matter what argument 
+//we pass to the function it will always take the value of the variable that we declared inside the function.
+//line 11 the computer will try to calculate the percentage but it will not reach this line because of the error in line 10.
+// line 13 the computer will try to print the value of decimalNumber but it will not reach this line because of the error in line 10. but if reach 
+// it will always print 0.5 no matter what argument we pass to the function.
+// in this case the error is "SyntaxError: Identifier 'decimalNumber' has already been declared" but if we fix it ,
+//then then console will give us the decimal number that we pass to the function in percentage format.
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  
+  const percentage = `${decimalNumber * 100}%`;
+
+  return percentage;
+}
+
+console.log(convertToPercentage(.45));