正则匹配问题

Question

$s = '{"name":xxx,"id":123456}{{"a":xxx,"id":147258,"b":xxx}{"c":xxx,"id":985236,"d":xxx}}';
echo preg_replace('/(?<="id":)[^,}]+/', '"$0"', $s);
{"name":xxx,"id":"123456"}{{"a":xxx,"id":"147258","b":xxx}{"c":xxx,"id":"985236","d":xxx}}

Answer 1

$s = '{"name":xxx,"id":123456}{{"a":xxx,"id":147258,"b":xxx}{"c":xxx,"id":985236,"d":xxx}}';
echo preg_replace('/("id":)([^,}]+)/', '$1"$2"', $s);解释版主的正则：
(?<="id":)：(?<=pattern)在任何匹配 pattern 的字符串结尾处匹配查找字符串，但是pattern 必须为定长（也就是"id":），非获取
[^,}]+：匹配除了“,”和“}”之外的任何字符至少一次，$0就是匹配到了内容

Answer 2

preg_replace('/(?<="id":)[^,}]+/', '"$0"', $s)
和
preg_replace('/("id":)([^,}]+)/', '$1"$2"', $s)
是一回事