全局使用javascript替换点_？

Question

im trying to replace all the dots and spaces in "

var name = "C. S. Lewis"

and replace them with _

and convert it into "C_S_LEWIS"

this is what i tried but it converts the whole thing into underscores ( _ )

var mystring = "C. S. Lewis";
var find = ".";
var regex = new RegExp(find, "g");
alert(mystring.replace(regex, "_"));

Answer 1

That's because dots need to be escaped in regular expressions (unless it's part of a character class). This expression should work:

var regex = /[.\s]+/g;

alert(mystring.replace(regex, '_'))

It matches a sequence of at least one period or space, which is then replaced by a single underscore in the subsequent .replace() call.

Btw, this won't save the new string back into mystring . For that you need to assign the results of the replacement operation back into the same variable:

mystring = mystring.replace(regex, '_')

Answer 2

The . means 'any character'. Use \\. to get a literal dot, which means in your regex string you'd have to put \\\\. to get a literal underscore followed by a literal dot. But I'm not sure why you're making a string first - you could just do this:

var find = /\./g;

Of course, that's not what you're looking for - you want not just any dot, but just the dots followed by spaces. That's different:

var find = /\.\s+/g;