java regex for 38k to 38000

Question

How do I change 38k to 38000? or 43k to 48000 etc

I tried this

String s0=toClean.replaceAll("[0-9]k", "[0-9]000");

But its wrong. It changes 38k to 309000

Answer 1

Not only one digit, but multiple (so add +). Also, you should capture that number and return it with the capture group 1 ($1) and check if there's nothing else after k (e.g. so as 38kabc wouldn't be valid)

String s0=toClean.replaceAll("([0-9]+)k\\b", "$1000");