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public class NumberUtils {
private NumberUtils() {}
// Check if given string is a number (digits only)
public static boolean isNumber(String string) {
return string.matches("^\\d+$");
}
// Check if given string is numeric (-+0..9(.)0...9)
public static boolean isNumeric(String string) {
return string.matches("^[-+]?\\d+(\\.\\d+)?$");
}
// Check if given string is number with dot separator and two decimals.
public static boolean isNumberWith2Decimals(String string) {
return string.matches("^\\d+\\.\\d{2}$");
}
public static void main(String[] args) {
System.out.println("42 valid ? " + NumberUtils.isNumber("42"));
System.out.println("42.1 valid ? " + NumberUtils.isNumber("42.1"));
System.out.println("42 valid ? " + NumberUtils.isNumeric("42"));
System.out.println("42.1 valid ? " + NumberUtils.isNumeric("42.1"));
System.out.println("-42.1 valid ? " + NumberUtils.isNumeric("42.1"));
System.out.println("-42.1a valid ? " + NumberUtils.isNumeric("42.1a"));
System.out.println("42.10 valid ? " + NumberUtils.isNumberWith2Decimals("42.10"));
System.out.println("42.101 valid ? " + NumberUtils.isNumberWith2Decimals("42.101"));
System.out.println("42,10 valid ? " + NumberUtils.isNumberWith2Decimals("42,10"));
System.out.println("42 valid ? " + NumberUtils.isNumberWith2Decimals("42"));
/*
* output
* 42.1 valid ? false
* 42 valid ? true
*
* 42.1 valid ? true
* -42.1 valid ? true
* -42.1a valid ? false
*
* 42.10 valid ? true
* 42.101 valid ? false
* 42,10 valid ? false
* 42 valid ? false
*/
}
}