Question

I need to add the regular expression in java to test the string whether it contains only alphanumeric( with or without “-“).
Ex:

ADB123
ABC-D1
12ABCD
A-BCD1   

etc.

Answer 1

You can try

for (String s : "ADB123,ABC-D1,12ABCD,A-BCD1,abcd12,a.b.c,12£".split(",")) {
    boolean ok = s.matches("[-\\p{Alnum}]+");
    System.out.println(s + " is ok: " + ok);
}

prints

ADB123 is ok: true
ABC-D1 is ok: true
12ABCD is ok: true
A-BCD1 is ok: true
abcd12 is ok: true
a.b.c is ok: false
12£ is ok: false

The regex [-\\p{Alnum}]+ means

• [ ]+ means one or more of any of the characters.
• - at the start means - not and not something else.
• \\ in a String literal turns into just \ as it is an escape character.
• \p{Alnum} is a predefined list of alpha and numeric characters.

See the documentation for Pattern for more details.