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foreach时加&符号：遍历的同时改变原数组即修改数据或者增加数据。 $arr = ['a', 'b', 'c']; foreach ($arr as $key => &$value) { $value = $value . '111'; } echo json_encode($arr); // ["a111","b111","c111"]，这里改变了原来数组的值 使用&可能出现的问题： $arr = ['a', 'b', 'c']; foreach ($arr as $key => &$value) { $value = $value . '111'; } foreach ($arr as $key => $value) { $value = $value . '222'; } echo json_encode($arr); // ["a111","b111","b111222222"] 这是由于在使用赋值引用传递之后没有释放$value的值，所以会影响第二个foreach的使用。可以使用unset($value)释放变量。 $arr = ['a', 'b', 'c']; foreach ($arr as $key => &$value) { $value = $value . '111'; } unset($value); // 释放$value的引用传递 foreach ($arr as $key => $value) { $value = $value . '222'; } echo json_encode($arr); // ["a111","b111","c111"]
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2022-08-17
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This affects all versions of package markdown-it-decorate. An attacker can add a
kostub/iosMath: Beautiful math equation rendering on iOS and MacOS
iqiukp/KPCA-MATLAB: MATLAB code for dimensionality reduction, feature extraction
mkyong/spring3-mvc-maven-annotation-hello-world: Maven + Spring 3 MVC hello worl
** DISPUTED ** Patlite NH-FB v1.46 and below was discovered to contain insuffici
微信小程序实现上下滚动消息提醒，主要是利用swiper组件来实现，swiper组件在小程序中
lizhuohua/linux-kernel-module-rust
cmaas/markdown-it-table-of-contents: A table of contents plugin for Markdown-it
Browsing the admin.html page allows the user to reset the admin password. Also a
hackl/tikz-network: A tool to visualize complex networks in LaTeX
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