finding whether a value exists in a javascript object with jquery

Question

I am trying to determine whether a object contains a specific value so that I can be sure not append the value I am looking for more than once and prevent recursion.

I have tried lots of methods but can't get any of them to work:

data = [
  {val:'xxx',txt:'yyy'},
  {val:'yyy',txt:'aaa'},
  {val:'bbb',txt:'ccc'}
];

console.log(jQuery.grep(data, function(obj){
    return obj.txt === "ccc";
}));
$.map(data, function(el) { 
    if(el.txt === 'ccc') 
        console.log('found')
});

Can this be done with map() grep() or inArray() or do I really have to loop through the entire array looking for the value ??

Joe · Accepted Answer · 2013-03-01 12:02:02Z

2

data is an array containing multiple objects, so you'll need to specify the index of the array you wish to look in:

data[0].val === 'xxx';
data[1].val === 'yyy';
data[2].txt === 'ccc';

As an update to your function, what's wrong with $.each? You're looping anyway with map or grep, so you may as well just be honest about it :P You can loop with for as well, but I'm exampling with $.each as it's almost identical to your current code.

$.each(data, function(el) { 
  if(el.txt === 'ccc') 
    console.log('found')
});

edited Mar 1, 2013 at 12:02

answered Mar 1, 2013 at 11:50

Joe

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Comments

gdoron · Accepted Answer · 2013-03-01 11:50:30Z

0

You will have to iterate the whole array as it's an array of objects, and comparing objects is done by the references not by the values.

for (var i = 0; i < data.length; i++){
    if (data[i].val == 'something')
        doSomething();
}

answered Mar 1, 2013 at 11:50

gdoron

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Comments

sasi · Accepted Answer · 2013-03-01 11:53:07Z

0

var stExist=$.inArray(reqelement, dataArray)

answered Mar 1, 2013 at 11:53

sasi

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gdoron · Accepted Answer · 2013-03-01 11:53:31Z

0

If you wish to avoid all this calculations yourself, there is a utility plugin underscore.js, which has lots of helper.

One of the helpers you are looking for http://underscorejs.org/#contains.

edited Mar 1, 2013 at 11:53

gdoron

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answered Mar 1, 2013 at 11:51

abhijit

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