PHP正則表達(dá)式函數(shù)preg_replace用法實(shí)例分析

$string = 'huang yu xin';
$pattern = '/(\w+) (\w+) (\w+)/i';
$replacement = '${1}a $3';
// $1對(duì)應(yīng)(\w+),${1}a是區(qū)別$1a,說明是$1和a不是$1a,$3對(duì)應(yīng)第三個(gè)(\w+)
echo preg_replace($pattern, $replacement, $string);

$string = "nice to meet you";
$pattern = array();
$replace = array();
echo preg_replace(array('/nice/', '/you/'), array('Nice', 'me'), $string);

$str = 'nice      !';
$str = preg_replace('/\s+/', '', $str);
echo $str;

$count = 0;
echo preg_replace(array('/\d/', '/[a-z]/'), '*', 'xp 4 to', -1, $count);
echo $count;