How to check if a string contains both letters and numbers?

Question

How can I check that the string contains both letters and numbers, both? As in the following example:

nickname1
nick1name
1nickname

I've seen a few examples of patterns, but none solves my problem, even most don't work

The situation is that in the application that I'm creating username must be a letter and number, so I need this...

You can check stackoverflow.com/a/11533559/290036 but with [a-zA-Z] — Horatiu Jeflea, Sep 03 '19 at 07:52
How is this Question too broad? Seems like a very specific problem to me. Thus I was able to give a very specific Answer. Voting to reopen. — Basil Bourque, Sep 05 '19 at 08:13

Basil Bourque · Accepted Answer · 2019-09-03T09:17:59.390

Unicode & `Character` class

What exactly do you mean by a letter? By a number?

Unicode defines those terms across the various human languages. In Java, the Character class provides convenient access to those definitions.

We can make short work of this using streams. Calling String::codePoints generates an IntStream. We can test each code point for being a letter or digit, until we find one.

String input = "nickname1" ;
boolean hitLetter = input.codePoints().anyMatch( i -> Character.isLetter( i ) ) ;
boolean hitDigit = input.codePoints().anyMatch( i -> Character.isDigit( i ) ) ; ;
boolean containsBoth = ( hitLetter && hitDigit ) ;

See this code run live at IdeOne.com.

Cyrille Con Morales · Answer 2 · 2019-09-03T07:50:32.917

1

Well maybe this can help you

String myUser = "asdsad213213";
if(myUser.matches("^[a-zA-Z0-9]+$")){

 //this is true
}

OR create a pattern

Pattern p = Pattern.compile("^[a-zA-Z0-9]+$");
Matcher m = p.matcher(inputstring);
if (m.find()){
//true
}

edited Sep 03 '19 at 07:50

answered Sep 03 '19 at 07:40

Cyrille Con Morales

918
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Sam · Answer 3 · 2019-09-03T07:54:26.447

1

private boolean checkUsername(String username)
{
String characters = "^[a-zA-Z]+$";
String numbers = "^[0-9]+$";

return username.matches(numbers) && username.matches(characters);
}

there you go, it first for numbers then for chars and when both exist you get a true value

edited Sep 03 '19 at 07:54

answered Sep 03 '19 at 07:45

Sam

31
4

How to check if a string contains both letters and numbers?

3 Answers3

Unicode & Character class

Unicode & `Character` class