這個(gè)為什么要加括號(hào)
$string?=?'April?15,?2014'; $pattern?=?'/(\w+)?(\d+),?(\d+)/i'; $replacement?=?'$3,?${1}?$2'; echo?preg_replace($pattern,?$replacement,?$string);?//結(jié)果為:2014,?April?15
為什么要加括號(hào),表示3個(gè)子組嗎?
$string?=?'April?15,?2014'; $pattern?=?'/(\w+)?(\d+),?(\d+)/i'; $replacement?=?'$3,?${1}?$2'; echo?preg_replace($pattern,?$replacement,?$string);?//結(jié)果為:2014,?April?15
為什么要加括號(hào),表示3個(gè)子組嗎?
2018-12-12
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