用js正则匹配1234567890出1234 56 78 90 我写的是var re=/（\d{4}）（\d{2}）（\d{2}）（\d{2}）/

匹配1234567890输出1234 56 78 90？

alert('1234567890'.replace(/^(\d{4})(\d{2})(\d{2})(\d{2})$/, '$1 $2 $3 $4'));