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Strange behavior Of foreach2个
> foreach loop and reference of &$value6个
这是我不理解的代码(作为输出).
> foreach loop and reference of &$value6个
这是我不理解的代码(作为输出).
<?PHP $x = ['test1','test2','test3','test4']; echo "First FOREACH\n"; foreach ($x as &$y) { echo $y."\n"; } echo "\n\nSecond FOREACH\n"; foreach ($x as $y) { echo $y."\n"; } ?>
输出：
First FOREACH test1 test2 test3 test4 Second FOREACH test1 test2 test3 test3
PS：我正在运行它：
PHP -v PHP 5.6.11-1ubuntu3.1 (cli) Copyright (c) 1997-2015 The PHP Group Zend Engine v2.6.0,Copyright (c) 1998-2015 Zend Technologies with Zend OPcache v7.0.6-dev,Copyright (c) 1999-2015,by Zend Technologies
在第一个foreach语句之后,你有$y指向最后一个数组项：
原文链接：https://www.f2er.com/php/135342.html$x = ['test1','test4']; $y =& $x[3];
每当您为$y分配一个值时,原始数组都将被修改.
当第二个foreach开始时,在每次迭代时,来自$x的下一个值被放入$y.因此,原始数组将如下所示：
// first iteration $x = ['test1','test1']; // second iteration $x = ['test1','test2']; // third iteration $x = ['test1','test3']; // fourth iteration $x = ['test1','test3'];
