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JavaScript JavaScript Loops, Arrays and Objects Tracking Data Using Objects Accessing All of the Properties in an Object

Posted by Jonathan Adams
Jonathan Adams
11,506 Points

I can't figure out why I am getting this error message.

I think I'm doing what the prompt is asking me to, so I'm not sure why I'm getting this wrong.

script.js 
var shanghai = {
  population: 14.35e6,
  longitude: '31.2000 N',
  latitude: '121.5000 E',
  country: 'CHN'
};

for (property in shanghai) {
  console.log(property);
}
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Objects</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

1 Answer

Zimri Leijen
Zimri Leijen
11,835 Points
Zimri Leijen
Zimri Leijen
11,835 Points 
for (let property in shanghai) {
  console.log(property);
}

if you omit 'let' it would work in non-strict mode, but that would pollute global scope.

use either var or let to declare the property in the for ... in loop. (technically you can use const as well).