How to understand this judgment ((Debug_mode & 2) = = 2)
((Debug_mode & 2) = = 2)//This sentence if set up, it is ((2 & 2) ==2) How to understand it?
Define (' Debug_mode ', false);//If 2 Yes, perform display 1
if ((Debug_mode & 2) = = 2)
{
$smarty = ' 1 ';
}
Else
{
$smarty = ' 0 ';
}
Echo $smarty;
?>
Copy code []
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"=&" What operator is this?
$user =& init_users ();
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is a reference, but adding & in front of the function really doesn't know what it's for.
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Bit operation and Operation Ah ...
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Let me explain.
In fact, the 2 here should be a fixed value, is to define your model of the constant, if this is good to understand
Define (' Mode_a ', 2);
$now _mode = 2;
if (($now _mode & mode_a) = = mode_a) {
echo "Current mode is Mode_a";
}
?>
Copy code Some classmates said, that why not = = Direct judgment, in fact, there is a meaning is included in the relationship
If the value of 6 & 2 is 2, and the value of 6&3 is 2, and 2! = 3
This approach can often represent a range, comparing the relationship between IP and subnet masks in a computer network
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Thanks to LS, your answer is well understood.
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Originally Posted by Lmhllr on 2007-12-17 17:27 [url=http://www.111cn.cn/bbs/redirect.php?goto=findpost&pid=335104&ptid= 46748] link marker [Img]http://www.111cn.cn/bbs/images/common/back.gif[/img][/url]
Bit operation and Operation Ah ...
Can you explain how he works? Or do you not understand the purpose of this writing?
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Originally Posted by Jayliu on 2007-12-17 16:55 [url=http://www.111cn.cn/bbs/redirect.php?goto=findpost&pid=335044&ptid= 46748] link marker [Img]http://www.111cn.cn/bbs/images/common/back.gif[/img][/url]
is a reference, but adding & in front of the function really doesn't know what it's for.
Added &
function return value is reference
PHP5 default is a reference, you can not use &, in PHP5 if the function directly return false, add & function is hung, PHP will not find the referenced address
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LS I learned something new. Thank you [img]http://www.111cn.cn/bbs/images/smilies/default/victory.gif[/img]
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Oh, that's it!
http://www.bkjia.com/PHPjc/632550.html www.bkjia.com true http://www.bkjia.com/PHPjc/632550.html techarticle How to understand this judgment ((debug_mode 2) = = 2)//This sentence if it is to be set up, it will be ((2//If 2 is, execute the display 1 if (Debug_mode} else {$smarty = ' 0 ';} echo $smarty;? &G T Copy ...
