用正则表达式匹配网址参数

Question

Im trying to extract url params with regex.

here is an example string: param1=val1&param2=val2&adv=val3&param3=val4&param4=val5

This is the regex im using right now:

(\&)([^=]+)\=([^&]+)

I can't figure out how to match the first param. I what to have param1 be in group 2 and val2 in group 3 like the rest of the param matches.

https://regex101.com/r/Qzxyyo/1

How can I do this?

edit: So this seems to work (meaning param1 is in group 2 and val1 in is group3). But I dont understand why it works or if it is reliable:

(\&|^)([^=]+)\=([^&]+)

Answer 1

(\&)([^=]+)\=([^&]+)

Break it down!

1. \\& look for a & character
2. [^=]+ match characters up until it hits a =
3. \\= match the = character
4. [^&]+ match characters up until &
5. () These define the groups!