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header前echo为啥不报错

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Jun 13, 2016 pm 12:03 PM

headernbspoutputphp

header前echo为什么不报错
不是说header前有输出就会报错吗？为什么下面这个代码正常呢

<?php<br /><br />echo "abc";<br />header("Location: http://www.baidu.com/");<br /><br />?>

------解决方案--------------------
当你的输出缓冲区打开时，就不会报错
查看 output_buffering 的值
------解决方案--------------------
ob_start() 打开的是用户输出缓冲区
而 output_buffering 是 php 系统输出缓冲区，php5.2及以前是默认关闭的
正因为一不留神就出错，所以php5.3及以后就默认打开了。

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