Finding the number of object properties

Question

I have the following JSON structure:

    {
        "codes":[
            {   
                    "id":"1",           
                    "code":{                
                        "fname":"S",
                        "lname":"K"

                }
            },
            {   
                    "id":"2",               
                    "code":{                
                        "fname":"M",
                        "lname":"D"                 
                }
            }
    ]
    }

I want to loop through each code and alert the number of properties within each code

        success: function (data) {               
            var x;
            for (x = 0; x < data.codes.length; x++){            
                alert(data.codes[x].id); // alerts the ID of each 'codes'
                alert(data.codes[x].code.length) // returns undefined
            }
    }

How do I do this?

Ben L · Accepted Answer · 2011-11-16 03:02:46Z

2

The problem is that "code" is an object, not an array. You can't get the length of an object in javascript. You'll have to loop through the object with a "for in" loop like below: (warning: untested).

success: function (data) {               
        var x, codeProp, propCount;
        for (x = 0; x < data.codes.length; x++){            
            alert(data.codes[x].id); // alerts the ID of each 'codes'
            propCount = 0;
            for (codeProp in data.codes[x]) {
                if (data.codes[x].hasOwnProperty(codeProp) {
                    propCount += 1;
                }
            }

            alert(propCount) // should return number of properties in code
        }
}

answered Nov 16, 2011 at 3:02

Ben L

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Comments

roselan · Accepted Answer · 2011-11-12 01:37:42Z

0

if (data && rowItem.code) {

or, if you like to do it directly:

if (data && data.codes[x].code) {

note, the check on "data" is useless, as your code loops elements of "data" (ie if data doesn't exist, data.codes.length can only be 0, and the for loop never starts)

answered Nov 12, 2011 at 1:37

roselan

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1 Comment

noob Over a year ago

@SK11 not data.rowItem.code, rowItem.code (how could data have the object rowItem)

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