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JavaScript JavaScript Loops, Arrays and Objects Tracking Data Using Objects Using `for in` to Loop Through an Object's Properties

Posted by Nelson Lourenco
Nelson Lourenco
1,766 Points

Not seeing output on FF 39 for Mac

var person = {
  name : 'Sarah',
  country : 'US',
  age : 35,
  treehouseStudent : true,
  skills : ['JavaScript', 'HTML', 'CSS']
};

for (prop in person) {
  console.log(prop, ': ');
}

When I goto the console tab of the native inspector, I don't see anything?

ericb2
ericb2
11,429 Points

I can eliminate one possiblity to simplify your troubleshooting. I had no trouble running your copy-and-pasted code in FF 39 on my Mac, so it is unlikely a browser bug.

Two simple problems I chronically run in to have cost me hours of needless troubleshooting: 1) I forget to save my script and/or refresh the page. and 2) I have to click twice (or maybe double click?) on the 'logging' tab of the console for the output to show up sometimes. This still baffles me.

good luck.

1 Answer

Abe Layee
Abe Layee
8,378 Points
Abe Layee
Abe Layee
8,378 Points

I believe the error is from your console.log(). You're also using concatenating the incorrect way. After the prop, you want have the + then follow by the person. Something like this.

var person = {
  name : 'Sarah',
  country : 'US',
  age : 35,
  treehouseStudent : true,
  skills : ['JavaScript', 'HTML', 'CSS']
};

for (prop in person) {
  console.log(prop + ': ' + person[prop]); // it should be like this.
}
Iain Simmons
Iain Simmons
Treehouse Moderator 32,305 Points

Actually using commas to pass multiple arguments to console.log is perfectly valid, though they were missing the last one person[prop].

They said that they weren't seeing anything in the console though.