Q:

Add brackets around digits

I have a string:

var string = {fld_1}-1000-{fld_1}

and I need to add {} around the digits 1000 (could be any number of digits though).
So the end string would be:

{fld_1}-{1000}-{fld_1}

My current regex is this:

var result = string.replace(/-(\d+)/g, '{$1}');

But I end up with this:

{fld_1}{1000}{1000}-{fld_1}

This is for a javscript application
Edit:
I should have noted that the strings could be this as well:

{fld_1}/1000-{fld_1}

or

{fld_1}+1000/{fld_1}

A:

Since \d is part of \w and [_+-] is not, you can use the word boundary assertion \b to your advantage:
'{fld_1}-1000-{fld_1}'.replace(/\b(\d+)\b/g, '{$1}')

Note that fld_1 is not replaced here, because _ is part of \w and as such there's no transition from \W to \w or vice versa.

