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JavaScript JavaScript Loops, Arrays and Objects Simplify Repetitive Tasks with Loops Refactor Using a Loop

Aiden Li
Aiden Li
10,399 Points

why does my code say 'Strict mode forbids implicit creation of global property 'i''?

i used a for loop but it came back with this and i dont know why

script.js
//console.log(2);
//console.log(4);
//console.log(6);
//console.log(8);
//console.log(10);
//console.log(12);
//console.log(14);
//console.log(16);
//console.log(18);
//console.log(20);
//console.log(22);
//console.log(24);

var even = 0;
for (i = 0; i < 13; i++) {
  even += 2;
  console.log(even);
}
index.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Loops</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

2 Answers

seth aruby
seth aruby
9,252 Points

Aiden, the following link may help: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode

What is likely happening here is that Treehouse's workspace codebase is applying strict mode which will require you to use the appropriate 'var i' syntax in your for loop. Hope this helps...

Adrian Rosario
seal-mask
.a{fill-rule:evenodd;}techdegree
Adrian Rosario
Front End Web Development Techdegree Student 13,468 Points

I had the same thing but i fixed by reading what you said, thanks!

const temperatures = [100, 90, 99, 80, 70, 65, 30, 10];

for (var i = 0; i < temperatures.length; i++) {

console.log(temperatures[i]);

}