Android How to check forcefully given string is alphanumeric or not

Question

I have tried this code. Its not working properly..

String myString = "343DFDFD"; // "FDFS343434"
System.out.println(myString.matches("[A-Za-z0-9]+")); //  false coming

note: i want output for above alphanumeric is true

Possible duplicate of [Fastest way to check a string is alphanumeric in Java](http://stackoverflow.com/questions/12831719/fastest-way-to-check-a-string-is-alphanumeric-in-java) — Aman Grover, Sep 16 '16 at 12:40

score 0 · Answer 1 · answered Sep 16 '16 at 12:44

0

Modify the regex as:

String myString = "343DFDFD"; // "FDFS343434"
System.out.println(myString.matches("^.*[^a-zA-Z0-9 ].*$")); //  false coming

answered Sep 16 '16 at 12:44

kgandroid

5,507
5
39
69

score 0 · Answer 2 · answered Sep 16 '16 at 13:11

Use it:

public boolean isAlphanumeric(String str) {
        for (int i=0; i<str.length(); i++) {
            char c = str.charAt(i);
            if (!Character.isDigit(c) && !Character.isLetter(c))
                return false;
        }

        return true;
    }

Android How to check forcefully given string is alphanumeric or not

2 Answers2