error predicted, code rewritten and explained

Author: zilinskyte

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

@@ -1,5 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The variable str is being declared twice within the same scope, which will cause a syntax error.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -8,6 +9,17 @@ function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+const result = capitalise('hello');
+console.log(result);
+// SyntaxError: Identifier 'str' has already been declared
 
 // =============> write your explanation here
+// // The first declaration is in the function parameter and the second one is inside the function body.
+// In JavaScript, you cannot declare the same variable name in the same scope using let or const.
+// To fix this, we can either rename the inner variable or assign the capitalised value to the parameter itself without redeclaring it.
+
 // =============> write your new code here
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}