Parsing JSON in JavaScript using a variable

Question

Was looking online for some help on this but couldn't find quite what I was looking for. I know how to parse a JavaScript variable, however, let's say I have the following JSON

  {
"CPU INFO": {
    "cpu0": "val",
    "cpu1": "someval"
   }
  }

Let's assume I don't know how many CPUs there are and I want to set keys of a dictionary to the values. For example, if I had a loop such as:

    for(var counterCPUS = 0; counterCPUS < numCPUs; counterCPUS++)
    {
        var currCPU = "cpu"+counterCPUS;
        dictionary["cpu"+counterCPUS] = furtherCPUObject.currCPU;
    }

Obviously this would not work since it would look for a String "currCPU", not "cpu0". How can I do what I am trying to achieve, assuming it is possible.

Thanks!

But [Iterate through object properties](http://stackoverflow.com/q/8312459/218196) might be more useful. — Felix Kling, Aug 31 '16 at 23:18
http://stackoverflow.com/questions/4244896/dynamically-access-object-property-using-variable This is what I was looking for, thanks. — trynacode, Aug 31 '16 at 23:21

Rob M. · Accepted Answer · 2016-09-01T00:04:40.450

2

You can iterate objects using for..in, or you can get the object's keys as an array by using Object.keys and iterate over that:

var json = {
  "CPU INFO": {
    "cpu0": "val",
    "cpu1": "someval"
  }
};

for (var cpuKey in json['CPU INFO']) {
   console.log(cpuKey, '=>', json['CPU INFO'][cpuKey]);
}
               
Object.keys(json['CPU INFO']).forEach(function(key) {
   console.log(key, '=>', json['CPU INFO'][key]);       
});

edited Sep 01 '16 at 00:04

answered Aug 31 '16 at 23:16

Rob M.

35,491
6
51
50

I'm sure you cannot use `for-of` to iterate over plain objects. – zerkms Aug 31 '16 at 23:57

Parsing JSON in JavaScript using a variable

1 Answers1