跳过字符串的一部分并用正则表达式替换匹配

Question

I need to replace part of a string but the code I have replaces the whole string and I want to only relace the text after the = equals sign based on the key name. I need the regular expression to skip the key word value= and then replace the value that it equals. I have part of it working in the regular expression but it does a full match.

    /(?:value\=)([A-Za-z{}": ',&-=\\]+)$/

name = test
key = value
value = {
  "first": 'John',
  'Last': 'Doe'
}
value = first = John & last = Doe

tester

 var data = "value=first_name=John&last_name=Doe;" .replace(/^(?:value\\=)([A-Za-z{}": ',&-=\\\\]+)$/g, 'first_name=Homer&last_name=Simspon'); console.log(data); /* data = value=first_name=John&last_name=Doe which should be value=first_name=Homer&last_name=Simspon */

Answer 1

You can use capturing groups, $1, $2, etc. I've used the wildcard .* regex below, but you could probably make it more specific to the key-val pairs you expect to see.

 var data = "value=first_name=John&last_name=Doe;" .replace(/(value\\=).*(;)/g, '$1first_name=Homer&last_name=Simspon$2'); console.log(data); /* data = value=first_name=John&last_name=Doe which should be value=first_name=Homer&last_name=Simspon */