Question

I’ve got a PHP array and echo that into javascript with json encode, i need to do it this way because it’s going to be very dynamic. This is the code it echo’s:

{"notempty":true}

And i use this to, convert it to javascript:

var myarray = eval('(' + json + ')');

For some reason it creates an object instead of an array and for that reason i cant use .length or a for loop.

Does someone know what im doing wrong here?

Thanks

Answer 1

You’re trying to treat an Object like an Array, and an Object is not an Array, it is an Object.

Any time you see {} in JSON, that means “What is contained within these hallowed brackets is a dynamic object”. When you see [], that means “Behold! I am an Array” (there are notable exceptions to this one: jQuery does some special work with to make itself look like an array).

So, in order to iterate through an Object, you’ll want to use for... in.

// eval BAD unless you know your input has been sanitized!.
var myObj = JSON.parse('{"notempty":true}');
// personally, I use it in for... in loops. It clarifies that this is a string
// you may want to use hasOwnProperty here as sometimes other "keys" are inserted
for( var it in myObj ) console.log( "myObj["+it+"] = " + myObj[it] );