Question

I have a PHP function that returns a multiple-level JSON object in the format

var data = {
  1 : { 
    1: { Object },
    2: { Object },
     ...,
     ...
  }, 
  2: {
    1: { Object },
    2: { Object },
    ...,
    ...
  }
}

I need to get the length of data to initialize a for loop maximum value. By this, I mean the count of the first level entries.

data[1].length returns 22, and data[2].length returns 23 via the console.log printout. This is expected, but data.length returns undefined.

Is there a better method than

var count = 0;

for (var i=1; i< Number.MAX_VALUE; i++){
  if (typeof data[i] != 'undefined')
    count = i;
}

Answer 1

If you can control the JSON format, nested arrays seem a better alternative.

If not, you can run something like

var length = 0;
for (var i in data) {
    if (isFinite(i) && i > length)
        length = i;
}