var str = ‘20160925120014‘; var date_str = str.replace(/(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})/g,‘$1-$2-$3 $4:$5:$6‘); console.log(new Date(date_str).getFullYear()+"-"+(new Date(date_str).getUTCMonth()+1)+"-"+new Date(date_str).getDate()+" "+new Date(date_str).getHours()+":"+new Date(date_str).getMinutes()+":"+new Date(date_str).getSeconds());
1.正则表达式
/(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})/g,‘$1-$2-$3 $4:$5:$6‘
此表达式是意思是第一组匹配连续4个数字，第二组匹配连续两个数字，第三组匹配连续两个数字，第四组匹配连续两个数字，第五组匹配连续两个数字，第六组匹配连续两个数字，然后把匹配到的6组数字分别存到$1,$2,$3,$4,$5,$6中
2.对于正则replace约定了一个特殊标记符$：
下面来几个demo:
"boy & girl".replace(/(\w+)\s*&\s*(\w+)/g,"$2 & $1") //girl & boy
"boy".replace(/\w+/g,"$&-$&") // boy-boy"javascript".replace(/script/,"$& != $`") //javascript != java"javascript".replace(/java/,"$&$‘ is ") // javascript is script原文：http://www.cnblogs.com/iagw/p/5909695.html