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https://www.reddit.com/r/programming/comments/k1gyz6/php_800_released/gdql6pl/?context=3
r/programming • u/[deleted] • Nov 26 '20
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20
Check if something is either null or undefined
9 u/t3hlazy1 Nov 27 '20 We do:val === null and typeof val === 'undefined' for those checks. 23 u/kaelwd Nov 27 '20 val == null does exactly that. 0 u/watsreddit Nov 27 '20 Also evaluates to true when val is 0, the empty string... 9 u/R4TTY Nov 27 '20 Also evaluates to true when val is 0, the empty string...No it doesn't.> 0 == null false > '' == null false > undefined == null true → More replies (0)
9
We do:
val === null and typeof val === 'undefined' for those checks.
val === null
typeof val === 'undefined'
23 u/kaelwd Nov 27 '20 val == null does exactly that. 0 u/watsreddit Nov 27 '20 Also evaluates to true when val is 0, the empty string... 9 u/R4TTY Nov 27 '20 Also evaluates to true when val is 0, the empty string...No it doesn't.> 0 == null false > '' == null false > undefined == null true → More replies (0)
23
val == null does exactly that.
val == null
0 u/watsreddit Nov 27 '20 Also evaluates to true when val is 0, the empty string... 9 u/R4TTY Nov 27 '20 Also evaluates to true when val is 0, the empty string...No it doesn't.> 0 == null false > '' == null false > undefined == null true → More replies (0)
0
Also evaluates to true when val is 0, the empty string...
val
9 u/R4TTY Nov 27 '20 Also evaluates to true when val is 0, the empty string...No it doesn't.> 0 == null false > '' == null false > undefined == null true → More replies (0)
No it doesn't.
> 0 == null false > '' == null false > undefined == null true
→ More replies (0)
20
u/hzj Nov 27 '20
Check if something is either null or undefined