Appropriate usage of == and === in JavaScript

Question

I'm new to Java Script What is the exact difference between (== Vs ===, != Vs !==, etc) in JavaScript? Have read some articles and wanted to be more clear on this. Thanks in advance.

if a function returns multiple values that are equivalent to false like 0, '0' or false (for example 0 means no result and false and error) and you want them to be treated the same then you can use == but if you want them to be treated differently then you have to use ===. — My1, Nov 13 '15 at 10:39

score 3 · Answer 1 · edited Apr 14 '14 at 21:18

3

The == operator means equality after type conversion

1 == '1';  // true
1 == 1;    // true

The === operator means equality without any conversion

1 === '1'; // false
1 === 1;   // true

edited Apr 14 '14 at 21:18

Paul S.

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answered Apr 14 '14 at 21:07

Timigen

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Ah so that's why `",,," == new Array(4);` returns `true`... :/ – Apr 14 '14 at 21:08
!= and !== do the same thing but consider inequality of values converted and of types. – Zini Apr 14 '14 at 21:11

Appropriate usage of == and === in JavaScript

1 Answers1