How to loop through JSON array?

Question

I have some JSON-code which has multiple objects in it:

[
    {
        "MNGR_NAME": "Mark",
        "MGR_ID": "M44",
        "EMP_ID": "1849"
    },
    {
        "MNGR_NAME": "Steve",
        "PROJ_ID": "88421",
        "PROJ_NAME": "ABC",
        "PROJ_ALLOC_NO": "49"
    }
]

My JSON loop snippet is:

function ServiceSucceeded(result) 
{       
  for(var x=0; x<result.length; x++) 
  {      

  }    
}

Could you please let me know how to check there is no occurence of "MNGR_NAME" in the array. (It appears twice in my case.)

does 'no' in your question mean 'number'?

Nikoloz Shvelidze
– Nikoloz Shvelidze

2011-12-13 12:35:51 +00:00
Commented Dec 13, 2011 at 12:35 — Nikoloz Shvelidze
– Nikoloz Shvelidze, Commented Dec 13, 2011 at 12:35

Abdul Munim · Accepted Answer · 2011-12-13 12:36:36Z

33

You need to access the result object on iteration.

for (var key in result)
{
   if (result.hasOwnProperty(key))
   {
      // here you have access to
      var MNGR_NAME = result[key].MNGR_NAME;
      var MGR_ID = result[key].MGR_ID;
   }
}

answered Dec 13, 2011 at 12:36

Abdul Munim

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1 Comment

Xogle Over a year ago

Your answer helped my JSON array rid itself from bad data. But why is that data getting sent through? How come you have to check that extra if?

Kees C. Bakker · Accepted Answer · 2011-12-13 12:42:27Z

7

You could use jQuery's $.each:

    var exists = false;

    $.each(arr, function(index, obj){
       if(typeof(obj.MNGR_NAME) !== 'undefined'){
          exists = true;
          return false;
       }
    });

    alert('Does a manager exists? ' + exists);

Returning false will break the each, so when one manager is encountered, the iteration will stop.

edited Dec 13, 2011 at 12:42

answered Dec 13, 2011 at 12:37

Kees C. Bakker

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1 Comment

Kees C. Bakker Over a year ago

If you want to count, you should not return false, of course.

Thomas Johan Eggum · Accepted Answer · 2011-12-13 12:43:12Z

2

Note that your object is an array of JavaScript objects. Could you use something like this?

var array = [{
    "MNGR_NAME": "Mark",
    "MGR_ID": "M44",
    "EMP_ID": "1849"
},
{
    "MNGR_NAME": "Steve",
    "PROJ_ID": "88421",
    "PROJ_NAME": "ABC",
    "PROJ_ALLOC_NO": "49"
}];

var numberOfMngrName = 0;
for(var i=0;i<array.length;i++){
    if(array[i].MNGR_NAME != null){
        numberOfMngrName++;
    }
}

console.log(numberOfMngrName);

answered Dec 13, 2011 at 12:43

Thomas Johan Eggum

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Comments

jabclab · Accepted Answer · 2011-12-13 12:37:08Z

0

This will find the number of occurrences of the MNGR_NAME key in your Object Array:

var numMngrName = 0;

$.each(json, function () {
    // 'this' is the Object you are iterating over
    if (this.MNGR_NAME !== undefined) {
        numMngrName++;
    }
});

answered Dec 13, 2011 at 12:37

jabclab

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Comments

Alex K. · Accepted Answer · 2011-12-13 12:37:39Z

0

Within the loop result[x] is the object, so if you wanted to count a member that may or may not be present;

function ServiceSucceeded(result)
{
  var managers = 0
  for(var x=0; x<result.length; x++)
  {
        if (typeof result[x].MNGR_NAME !== "undefined")
            managers++;
  }
  alert(managers);
}

answered Dec 13, 2011 at 12:37

Alex K.

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Comments

Steffen Stenersen · Accepted Answer · 2011-12-13 12:41:12Z

0

You can iterate over the collection and check each object if it contains the property:

var count = 0;
var i;
for(i = 0; i < jsonObj.length; i += 1) {
    if(jsonObj[i]["MNGR_NAME"]) {
        count++;
    }
}

Working example: http://jsfiddle.net/j3fbQ/

answered Dec 13, 2011 at 12:41

Steffen Stenersen

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Comments

kgiannakakis · Accepted Answer · 2011-12-13 12:42:53Z

0

You could use $.each or $.grep, if you also want to get the elements that contain the attribute.

filtered = $.grep(result, function(value) {
    return (value["MNGR_NAME"] !== undefined)
});
count = filtered.length

edited Dec 13, 2011 at 12:42

answered Dec 13, 2011 at 12:37

kgiannakakis

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Comments

user1349544 · Accepted Answer · 2018-09-28 07:51:49Z

0

Use ES6...

myobj1.map(items =>
{
if(items.MNGR_NAME) {
return items.MNGR_NAME;
}else {
//do want you want.
}    
})

Thanks.

answered Sep 28, 2018 at 7:51

user1349544

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