How should i get some value from javascript object and check for null

Question

I am getting the element as

   var minPricePerInputField = $("input#A"+indexNr);

The element can be present also or not also. I am getting some [object Object] thing. I have no idea what is this. I am receiving this [object Object] when the element is not there.

If you use firebug (or another similar) you could breakpoint the code in the browser and take a look at the object, this would help you no end. — RubbleFord, Jul 21 '11 at 06:58

score 1 · Accepted Answer · answered Jul 21 '11 at 06:58

1

Use

if(   $(minPricePerInputField).length === 0);

means null. no element for that selector.

answered Jul 21 '11 at 06:58

Vivek Goel

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@Saurabh Kumar nops It will be "===". Read http://stackoverflow.com/questions/3735939/jslint-expected-and-instead-saw for more details. – Vivek Goel Jul 21 '11 at 07:05

score 1 · Answer 2 · answered Jul 21 '11 at 06:58

1

You are recieveng jQuery object. When there's no such an element, the length property of the recieved object will be 0.

answered Jul 21 '11 at 06:58

Igor Dymov

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score 0 · Answer 3 · answered Jul 21 '11 at 06:57

[object Object] is the default toString() of an Object.

When the Object is used in a String context, the toString() is called implicitly.

Whether jQuery matched 0 or more elements won't affect the toString().

jsFiddle.

You can check the length property to check if the selector matched any elements.

jsFiddle.

score 0 · Answer 4 · answered Jul 21 '11 at 06:57

0

to get the value of an object.. use object.property

Best way: using jQuery ...see the data by console.log(minPricePerInputField)

answered Jul 21 '11 at 06:57

xkeshav

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This will log `[Object object]`. Even if no matching elements are found, a transient jQuery object will still be created and returned... – Björn Jul 21 '11 at 07:04

score 0 · Answer 5 · answered Jul 21 '11 at 06:59

0

var minPricePerInputField = $("input#A"+indexNr);

if(minPricePerInputField.size()==1)
{
   //element exists do something
}

answered Jul 21 '11 at 06:59

Praveen Prasad

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score 0 · Answer 6 · answered Jul 21 '11 at 06:59

0

if($("input#A"+indexNr).length == 1){
      alert("Im present");
    }

answered Jul 21 '11 at 06:59

vhtellez

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score 0 · Answer 7 · answered Jul 21 '11 at 07:01

0

you can check count of selected element count.

var minPricePerInputField = $("input#A"+indexNr);
if(minPricePerInputField.length == 0){
   return;
}

answered Jul 21 '11 at 07:01

Ethem Kuloglu

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How should i get some value from javascript object and check for null

7 Answers7