Java Regex match and replace

Question

I have set of some characters as below :

[A-Za-z0-9/-?:().,’+#=! ” %& * <>; {@\r\n]

I have to write a program in java to make sure input is not having any character out of this set and if they do, I have to replace them with spaces.

How can I achieve this ? Only Java 6 please.

Also, when you say "out of this set", do you mean you want to replace characters that are _in_ this set, or that are _not in_ this set? — tobias_k, Jun 16 '16 at 11:37

engineer14 · Answer 1 · 2016-06-16T11:58:55.273

1

String str = str.replaceAll("([^A-Za-z0-9/\\-?:\\(\\)\\.,’\\+#=! \\” %& \\* <>; \\{@\\r\\n])", " ")

Basically, if you have a set that is not in "abc", you use the caret to negate the group --> [^abc]

Here is a great guide to better using regex: http://www.regular-expressions.info/

And if you want to test, here is another great tool: https://regex101.com/

edited Jun 16 '16 at 11:58

answered Jun 16 '16 at 11:34

engineer14

3

`"\s"` is not a valid replacement string. It's a character class; how would Java know what of those chars to replace with? – tobias_k Jun 16 '16 at 11:35
2

This won't work in java. You'll have to escape slashes. – Abdul Fatir Jun 16 '16 at 11:36
Why are we encouraging this terrible question with an answer? – rmlan Jun 16 '16 at 11:44

score 0 · Answer 2 · answered Jun 16 '16 at 11:46

0

Do the following. [A-Z] matches anything in the range while [^A-Z] matches anything not in the range. This will work in Java.

String out = input.replaceAll("[^A-Za-z0-9\\/\\-?:().,\'+#=!\"%&*<>;{@\\r\\n]", " ");

answered Jun 16 '16 at 11:46

Abdul Fatir

2 Answers2