How to use "[" and "]" in Regex

Question

i have this Regex in my Java program

if(Function.match(strAddress, "[~|+_=!$%^*@`(){}:;\"'<>?,]++"))
--do something

I want to include [ and ] in regex as well. I tried using escape characters as well but no go. How do I add these characters to my regex?

Use this example

public class test {

    public static void main(String[] args) {
        String text = "asda[]";
        System.out.println("Test: "+ text.matches("[~|+_=!$%^*@`(){}:;\"'<>?,\\[\\]]++"));
    }
}

I tried with \[ and [, its not working

Last run on above code gave output Test: false

String.matches has an implied start anchor and end anchor. Your test returns false because the string is not comprised entirely of punctuation. Try putting `[a-z]*` at the start of your pattern. — VGR, Jun 02 '17 at 15:29

YCF_L · Accepted Answer · 2017-06-02T15:47:36.770

2

try to use :

"[~|+_=!$%^*@`(){}:;\"'<>?,\\[\\]]++"
//-------------------------^^-^^

You have to escape this two character with \\

Edit

of course it match only this group of characters

~|+_=!$%^*@`(){}:;\"'<>?,[]

but in your example you are using alphabetic, so instead you have to include a-z for lower character, and A-Z to matches also the upper characters :

[a-z~|+_=!$%^*@`(){}:;\"'<>?,\\[\\]]++
 ^^^-------------------------------

Now for your example :

String text = "asda[]";
System.out.println("Test: " + text.matches("[a-z~|+_=!$%^*@`(){}:;\"'<>?,\\[\\]]++"));

it return:

Test: true

EDIT

You can go with this solution :

[a-z]*[~|+_=!$%^*@`(){}:;\"'<>?,\[\]]++

which will gives you :

abc[]  -> true
[]     -> true
abc    -> false
[]abc  -> false

edited Jun 02 '17 at 15:47

answered Jun 02 '17 at 15:15

YCF_L

51,266
13
85
129

I tried, I have updated the question with example too – uSeruSher Jun 02 '17 at 15:27
check my edit @uSeruSher – YCF_L Jun 02 '17 at 15:36
If you run with "ASD" then also it will say true. I want true ONLY in case of specail characters as listed in regex – uSeruSher Jun 02 '17 at 15:39
then you can remove A-Z the upper letters @uSeruSher – YCF_L Jun 02 '17 at 15:40
What i mean is only asd, ASD, etc. should give result as false, i want only ~|\\[\\]+_=!$%^*@`(){}:;\"'<>?,++[] to give true. – uSeruSher Jun 02 '17 at 15:41
@uSeruSher you want to match an alphabetic + special character or only special characters? – YCF_L Jun 02 '17 at 15:45
@uSeruSher check my 3rd solution hope this is what you mean – YCF_L Jun 02 '17 at 15:48
yeah that works :) – uSeruSher Jun 02 '17 at 18:08
you are welcome :) – YCF_L Jun 02 '17 at 18:14

How to use "[" and "]" in Regex

1 Answers1