正则表达式测试字符串是否包含数字

Question

I wanted to test if a string contains numbers (at least one number) so I tried out this:

public class Test {
private static final String DIGIT_PATTERN = "^(?=.*\\d)";
private static final Pattern DIGIT_PATTERN_COMPILED = Pattern.compile(DIGIT_PATTERN);

/**
 * 
 * @param args
 */
public static void main(String[] args) {
    String passwordOne = "123";
    String passwordTwo = "abc";

    Matcher matcher = null;

    matcher = DIGIT_PATTERN_COMPILED.matcher(passwordOne);

    if(!matcher.matches()) {
        System.out.println("Password " + passwordOne + " contains no number");
    } else {
        System.out.println("Password " + passwordOne + " contains number");
    }

    matcher = DIGIT_PATTERN_COMPILED.matcher(passwordTwo);

    if(!matcher.matches()) {
        System.out.println("Password " + passwordTwo + " contains no number");
    } else {
        System.out.println("Password " + passwordTwo + " contains number");
    }   
}
}

Unfortunately both if clauses print out that it contains no number. Am I using the regex wrong?

Answer 1

试试下面的正则表达式：

private static final String DIGIT_PATTERN = "\\d+";

Answer 2

Why not just use

private static final String DIGIT_PATTERN = "\\d";

That should match if there's any number in there.

Answer 3

The most basic pattern

".*[0-9].*"

works for me with your code.