javascript - masalah format tarikh penggantian biasa js

Question

'2017-6-5'.replace(/-(\d{1})$|-/g,'0'),返回为什么是20170605，少了"-"，我要的结果是2017-06-05

Answer 1

'2017-6-5'.replace(/-(d{1})/g,'-0') Cuba tulis begini.