php中&&与&有什么区别
第一个:&&是逻辑运算符,代表“并且”也就是常说的 AND。常见的还有如下几个:
!$a Not(逻辑非) TRUE,如果 $a 不为 TRUE。
$a && $b And(逻辑与) TRUE,如果 $a 与 $b 都为 TRUE。
$a || $b Or(逻辑或) TRUE,如果 $a 或 $b 任一为 TRUE。
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第二个:&是位运算符,$c = $a & $b, 将把 $a 和 $b 的二进制位中都为 1 的位设为 1。
如5&3 =>101 & 11 这个是二进制

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