Using Javascript non-capturing group in a replace

Question

The expression

"abcb".replace(/(?:a)b/, 'x')

returns "xcb". What I want it return is "axcb"; that is, the "a" is not captured.

Is this possible in a single regex?

Answer 1

You can make it capturing:

"abcd".replace(/(a)b/, '$1x')
//=> axcd