正则表达式替换所有前导字符而不是a-Z

Question

I need to replace all non-letter characters that appear at the start before any letter for example

$ %5hello w8r^ld becomes hello w8r^ld

This regex I got now works greate for replacing none word characters but does not replace numbers

s.replaceFirst("^[\\W_]+", "")

Answer 1

You are using the wrong character class. Use

s.replaceFirst("^[^a-zA-Z]+", "")

That is

^          start at the beginning of the string
[^  ]+     one or more (greedy - keep going until you hit a letter
a-zA-Z     ascii characters between a-z or A-Z

Following comments from @anubhava, I changed the * to a + . If you have no match, there is nothing that needs replacing. It's actually cleaner.