Computer scienceProgramming languagesJavaAdditional instrumentsRegular expressions

Patterns and Matcher

Theory

Number parsing

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You need to write a regular expression that can match any number.

A number can be positive or negative. If it is negative, then it must start with a '-'. If it is positive, it may start with a '+'. If it doesn't start with either '+' or '-' it is considered positive.

A number representation can't be padded with leading zeroes. For example, 001 is not a valid number (but 0 is).

A number can have a fractional part. A delimiter between an integer part and a fractional part can be either a dot . or a comma ,. A fractional part can't be padded with trailing zeros: for example, 1.01 and 1.0 are valid numbers, but 1.00 and 1.10 are not.

Output "YES" if a given string is a valid number, otherwise output "NO".

Sample Input 1: 

123

Sample Output 1: 

YES

Sample Input 2: 

0123

Sample Output 2: 

NO

Sample Input 3: 

-56.0

Sample Output 3: 

YES

Sample Input 4: 

-0,05

Sample Output 4: 

YES

Sample Input 5: 

-23.230

Sample Output 5: 

NO

Sample Input 6: 

+12376352189432535347623423443417,36817231873134176345178234234234234

Sample Output 6: 

YES
Write a program in Java 17
import java.util.Scanner;

public class Main {

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);

String regex = "write-your-regex-here";

String number = scanner.nextLine();
System.out.println(number.matches(regex) ? "YES" : "NO");
}
}
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