javascript pattern replacement using backreference is not working

string.replace(/([\开发者_如何学Pythont])/g,"\\$1")

is working fine where

string.replace(/([\n])/g,"\\$1")

is not working!!!

any idea please???

N.B.

string.replace(/\n/g,"\\\n")

is also working fine

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Use a script to capture the enter keypress event and replace it with '\' prior to submission.