Regex: Unable to do negative lookahed

Question

Here's my input text:

Intel Core i3-4170 3.7GHz

I'm trying to replace 3.7GHz with XXX

Here's my pattern:

/\s(?=[^\s]+(.*?GHz)$)/

but this matches: i3-4170 3.7GHz

if I add the global flag I get what I need in the 2nd group, but I'm not sure if that's reliable.

https://regex101.com/r/ARa1tG/1

Answer 1

Another way can be - more specific - :

/[\d.]*\dGHz/g

[Regex Demo]

Answer 2

My answer:

\b\d+(?:\.\d+)?ghz\b

\b    // word boundary
\d+   // 1 or more digits
(?:   // optional group (not captured)
\.\d+ // a dot, then 1 or more digits
)?    // end of group
ghz   // literal
\b    // word boundary 

• Flags: g, i
• Steps: 91

Demo

Answer 3

you can use the regex

\b[^\s]*GHz\b

see the regex 101 demo