23 lines
606 B
Java

package com.baeldung.stringisnumeric;
import static org.assertj.core.api.Assertions.assertThat;
import org.junit.Test;
public class RegularExpressionsUnitTest {
public static boolean isNumeric(String strNum) {
return strNum.matches("-?\\d+(\\.\\d+)?");
}
@Test
public void whenUsingRegularExpressions_thenTrue() {
// Valid Numbers
assertThat(isNumeric("22")).isTrue();
assertThat(isNumeric("5.05")).isTrue();
assertThat(isNumeric("-200")).isTrue();
// Invalid Numbers
assertThat(isNumeric("abc")).isFalse();
}
}