How to prevent javascript if statement to evaluate 0 as an empty string?

Question

I have js object that has data which contains numbers. Some of them can be 0. In that case if statement will evaluate those values as an empty strings. Here is example:

var dataObj = {
  "one": 13,
  "two": 0,
  "three": 3
}

$.each(dataObj, function (j, k) {
  if(k){
    console.log('Column: '+k);
  }else{
    console.log('Empty');
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

I'm wondering how this can be prevented? Is there a way to check if value is empty but at the same time not consider 0 as an empty value?

Why wouldn't it be? It's guaranteed to behave in a specific way by the language spec. — Pointy
– Pointy, Commented Dec 12, 2018 at 14:59
So do not do a truthy check? Check for an empty string? if (k != '') — epascarello
– epascarello, Commented Dec 12, 2018 at 15:03
Is not evaluating as empty string. There are numerous falsy values beyond empty string and 0 is one of them — charlietfl
– charlietfl, Commented Dec 12, 2018 at 15:05

hifebriansyah · Accepted Answer · 2018-12-12 15:07:13Z

2

you can change the condition to k || k===0 this mean (as far as i know) it will accept not-undefined, not-null, not-empty and zero int value as a true.

please comment if there anything i can do to improve the answer..

don't forget to checkout my snippet

have a nice day..

var dataObj = {
  "one": 13,
  "two": 0,
  "three": 3,
  "four": null,
  "five": ''
}

$.each(dataObj, function (j, k) {
  // use 'or' operator
  if(k || k===0){
    console.log('Column: '+k);
  }else{
    console.log('Empty');
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

edited Dec 12, 2018 at 15:07

answered Dec 12, 2018 at 14:59

hifebriansyah

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Comments

Mamun · Accepted Answer · 2018-12-12 15:09:45Z

0

You can add k==0 with Logical operator (||) as part of the condition which will pass through the condition when the value is 0.

Try

if(k || k == 0){

var dataObj = {
  "one": 13,
  "two": 0,
  "three": 3
}

$.each(dataObj, function (j, k) {
  if(k || k == 0){
    console.log('Column: '+k);
  }else{
    console.log('Empty');
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

edited Dec 12, 2018 at 15:09

answered Dec 12, 2018 at 15:00

Mamun

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2 Comments

user5734311 Over a year ago

Sorry, but this a duplicate of a previous answer (and should be a comment anyway, given that this is a question about good practice, not really about solving a problem)

Mamun Over a year ago

@ChrisG, why the comment is only under one answer not under another.....voting to close would be more meaningful than commenting.

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