如果不等效 在什么地方会有区别？
This topic created in 4017 days ago, the information mentioned may be changed or developed.
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1
xuxu Jun 8, 2015
$foo没定义时 if($foo) 会报warning.
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2
manhere Jun 8, 2015
$foo = 0;
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3
Ison Jun 8, 2015
var_dump
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4
fangjinmin Jun 8, 2015
不一样，看函数定义吧。empty对于0, "", 0.0, "0", array(), NULL, FALSE, 没赋值的$var都认为是TRUE.
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5
oott123 Jun 8, 2015
> No warning is generated if the variable does not exist. That means empty() is essentially the concise equivalent to !isset($var) || $var == false.
via http://php.net/manual/en/function.empty.php 也就是说，在 $var 未定义的时候不等效。 |
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6
bombless Jun 8, 2015
应该是 if(isset($foo) && $foo)
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7
wavingclear Jun 9, 2015
@bombless 1楼是对的
isset 和 empty 同是语言结构，所以那样写没啥意义…… |
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8
cevincheung Jun 9, 2015
@xuxu notice
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