how to check properties object is there or not ? jquery

Question

I have some problem, I have an array like this

var obj = [{'person': {'name: 'foo', 'email': 'email.com'}, {'person': {'name: 'foo'}]

if i loop inside var obj, and want to get value email like this :

$.each(obj, function(index, value) {
    console.log(value.person.email)
}

if I do like that, it shows an error because cannot read the property email.

how I pass it when the person does not have email ? or is there a way to create conditions like isset on php

Use [`hasOwnProperty`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty) — Rory McCrossan, Jan 22 '20 at 09:46
or take [`in` operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/in). — Nina Scholz, Jan 22 '20 at 09:47
There are similar questions you can hopefully relate your code to: https://stackoverflow.com/questions/19590865/from-an-array-of-objects-extract-value-of-a-property-as-array — Jason Is My Name, Jan 22 '20 at 10:06

score 0 · Answer 1 · answered Jan 22 '20 at 09:50

You can use in operator to check if object has that key present or not like this.

Please note, there is the syntax error in your array. I have corrected it.

var obj = [{'person': {'name': 'foo', 'email': 'email.com'}}, {'person': {'name': 'foo'}}];

$.each(obj, function(index, value) {
  if ('email' in value.person){
    console.log(value.person.email);
  }      
});

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

score 0 · Answer 2 · answered Jan 22 '20 at 09:52

You can use simple !! which will return boolean value.

var obj = [{'person': {'name': 'foo', 'email': 'email.com'}}, {'person': {'name': 'foo'}}];

$.each(obj, function(index, value) {
    if(!!value.person.email){
      console.log(value.person.email);
    } else {
      console.log("Email not available");
    }
});

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

how to check properties object is there or not ? jquery

2 Answers2