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I found this somewhere: Instead of if (count != undefined && count != null), use if(count != null). Can I use if (count == null) and if(!count) interchangeably?

Prashant
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    `count != undefined && count != null` is *exactly* the same as `count != null`. `!count` is true if `count` is `null`, `undefined`, `0`, `NaN`, the empty string, or `false`. (Converted to an answer while I look for a duplicate) – Ry- Aug 18 '16 at 09:44
  • https://dorey.github.io/JavaScript-Equality-Table/ – Etheryte Aug 18 '16 at 09:44

1 Answers1

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count != undefined && count != null is exactly the same as count != null. !count is true if count is null, undefined, 0, NaN, the empty string, or false.

Ry-
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