php:<\/p>\n
preg_match ($preg ,$str,$match); \u662f\u5426\u5339\u914d\u5230<\/p>\n
preg_match_all ($preg ,$str,$match); \u5339\u914d\u6570\u91cf $match\u53ef\u4ee5\u4e0d\u52a0<\/p>\n
var_dump ( $match );<\/p>\n
$preg='\\a\\'; a\u4e3a\u6b63\u5219\u8868\u8fbe\u5f0f<\/p>\n
\\w \u4e00\u4e2a\u5b57\u7b26 \\d \u4e00\u4e2a\u6570\u5b57 \\s\u7a7a\u683c\u56de\u8f66<\/p>\n
\\W \\D \\S \u524d\u9762\u53d6\u8865\u96c6<\/p>\n
[A-Z] \u533a\u95f4<\/p>\n
[^A-Z] \u533a\u95f4\u53d6\u8865\u96c6<\/p>\n
\\w|\\d |\u6216\u8fd0\u7b97<\/p>\n
^x \u5f3a\u5236\u5339\u914d\u884c\u9996<\/p>\n
x$ \u5f3a\u5236\u5339\u914d\u884c\u5c3e \uff08\u6700\u591a\u5339\u914d1\u6b21\uff09<\/p>\n
\\d{4} \u5339\u914d\u8fde\u7eed\u51fa\u73b04\u6b21 \uff08\u20181234\u2019\uff0c\u20182222\u2019\uff09<\/p>\n
\\d(i,j) \u5339\u914d\u8fde\u7eed\u51fa\u73b0i\u5230j\u6b21<\/p>\n
\\d? 0<=k<=1 <-\u5339\u914d\u6b21\u6570 \\d+ k>=1<\/p>\n
\\d* k>=0<\/p>\n
\\\\1 \u8868\u793a\u672c\u6b21\u5339\u914d\u4e2d\u7b2c\u4e00\u4e2a\u51fa\u73b0\u7684\uff08\uff09\u4e2d\u7684\u5185\u5bb9<\/p>\n
*? \u5339\u914d\u5c3d\u53ef\u80fd\u77ed<\/p>\n","protected":false},"excerpt":{"rendered":"
php: preg_match ($preg ,$str,$match); \u662f\u5426\u5339\u914d\u5230 preg_match_ […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","footnotes":""},"categories":[12],"tags":[],"class_list":["post-490","post","type-post","status-publish","format-standard","hentry","category-algorithm"],"yoast_head":"\n