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# Java program to check a given character is a digit or not without using the built-in library method

Given/input a character, we have to check a given character is a digit or not without using the built-in library method.
Submitted by Nidhi, on February 24, 2022

## Problem statement

In this program, we will read a character from the user and check the input character is a digit or not without using any built-in library method.

## Java program to check a given character is a digit or not

The source code to check a given character is a digit or not without using the built-in method is given below. The given program is compiled and executed successfully.

```// Java program to check a given character is a
// digit or not without using the
// built-in library method

import java.util.Scanner;

public class Main {
static boolean isDigit(char ch) {
if (ch >= '0' && ch <= '9')
return true;
return false;
}

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

char ch = 0;

System.out.printf("Enter character: ");
ch = X.next().charAt(0);

if (isDigit(ch))
System.out.printf("Given character is a digit\n");
else
System.out.printf("Given character is not a digit\n");
}
}
```

### Output

```RUN 1:
Enter character: 8
Given character is a digit

RUN 2:
Enter character: R
Given character is not a digit

RUN 3:
Enter character: &
Given character is not a digit
```

## Explanation

In the above program, we imported the "java.util.Scanner" package to read input from the user. And, created a public class Main. It contains two static methods main() and isDigit().

The isDigit() method returns a Boolean value based on input character, it returns true if a given character is a digit otherwise it returns false.

The main() method is an entry point for the program. Here, we read a character from the user and checked input character is a digit or not and printed the appropriate message.