In php, why does empty ("0") return true?
According to php documentation, following expressions return true when called empty($var)
- "" (empty line)
- 0 (0 as integer)
- 0.0 (0 as float)
- "0" (0 as string)
- NULL
- FALSE
- array () (empty array)
- $ var; (declared variable, but no value)
I found how to "solve" the problem using empty($var) && $var != 0
, but why did the php developers do this? i think it's funny, suppouse you have this code:
if (empty($_POST["X"])) {
doSomething();
}
I think "0"
not empty, empty when there is nothing !!! it might be better to use
if (isset($x) && x != "") {//for strings
doSomething();
}
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empty
coarse mirror PHP selection of FALSE-y values :
When converted to boolean, the following values are considered FALSE:
- the logical FALSE itself
- integer 0 (zero)
- float 0.0 (zero)
- empty string and string "0"
- array with zero elements
- ...
To what extent PHP works this way or why the empty function followed suit - well, it's just the way it is.
Consider using strlen($x)
(this works especially well for sources such as $_POST
which are all string values) to determine if a non-empty string exists, including "0".
The last form I use would then be:, isset($x) && strlen($x)
with any additional processing used knowing there is some data to post.
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