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

Richard Stover
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Richard Stover
Full Stack JavaScript Techdegree Student 8,838 Points
Posted by Richard Stover
.a{fill-rule:evenodd;}techdegree
Richard Stover
Full Stack JavaScript Techdegree Student 8,838 Points

Challenge task code global property error

I am receiving an error with the attached code and do not see the reason.

"Bummer: There was an error with your code: ReferenceError: Strict mode forbids implicit creation of global property 'test'"

Can someone please point out the syntax error to me?

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

for (test in shanghai){
 console.log(test); 
}
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

Nicole Antonino
Nicole Antonino
12,834 Points
Nicole Antonino
Nicole Antonino
12,834 Points

You didn't write the correct syntax. You forgot to declare with a const at the beginning. So yours should look like this:

for (const test in shanghai){
 console.log(test); 
}

For reference here is the correct syntax according to the MDN:

Richard Stover
seal-mask
.a{fill-rule:evenodd;}techdegree
Richard Stover
Full Stack JavaScript Techdegree Student 8,838 Points
Richard Stover
.a{fill-rule:evenodd;}techdegree
Richard Stover
Full Stack JavaScript Techdegree Student 8,838 Points

huh..I had a feeling it was variable declaration thing.

But then why did my original code work in a blank workspace I pasted it into?

Nicole Antonino
Nicole Antonino
12,834 Points
Nicole Antonino
Nicole Antonino
12,834 Points

Not sure! Hard to say without seeing the code directly. But if you declared a variable with the same name before the for...in loop then that might have done it.