Question

I need to escape characters like ^, ., [, ], + and \ (tabs and newlines won’t be an issue), while leaving others like * and ?.

EDIT = More specifically, I have a string with these characters, and I need to escape them so that they are not matched by regular expressions. I need to prepend \ to each of these characters, but doing so individually would take 7 or 8 scans and I’d like to do it within just one pass (IE: anything that matches is prepended with \)

How do I do this?

Thanks.

Answer 1

Would this work?

StringBuilder sb = new StringBuilder();
for (char c : myString.toCharArray())
{
    switch(c)
    {
        case '[':
        case ']':
        case '.':
        case '^':
        case '+':
        case '\\':
            sb.append('\\');
            // intended fall-through
        default:
            sb.append(c);
    }
}
String escaped = sb.toString();