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

for in loop, javascript

Usually I have some idea of what's going wrong, but not so much here. The video didn't really clear it up. I'm not really getting how two variables can go through this one loop.

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

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

2 Answers

Michael Hulet
MOD
Michael Hulet
Treehouse Moderator 47,826 Points

There won't really be 2 variables going through this loop. With the code you've written, the loop will go over each property in shanghai and set the variable you declared called property to the key that the loop is currently on. With the first iteration, property will be "population", and it'll be "longitude" on the 2nd, "latitude", on the 3rd, and finally "country" on the last. Remember that you can access an object's property via subscript syntax, like this:

const myObject = {someProperty: 5};

console.log(myObject["someProperty"]); // This will log the number 5

Keeping those things in mind you should have the tools to pass the challenge. You're doing great, and you're almost there!

I'm finished with the course except for this question. I thought that going through more of the videos would help me put it together, but I just don't get it. At all. It keeps telling me that I'm passing the property value and not the name no matter what I try.

Michael Hulet
Michael Hulet
Treehouse Moderator 47,826 Points

That's ok, we're all still happy to help. Struggling a bit is totally normal. Just so I know where you are, is the latest code you've tried still the same as in your question? If not, I'd love to see where you are now