Q:

# Java program to convert number from Decimal to Hexadecimal

This program will convert integer (Decimal) number to its equivalent Hexadecimal Number.
There are two programs:
1) Without using any predefine method and
2) Using Integer.toHexString() method.

## Without using any predefine method

``````// java program to convert decimal to hexadecimal

import java.util.*;

public class CovDec2Hex {
public static void main(String args[]) {
int num, counter = 0;
Scanner sc = new Scanner(System.in);

System.out.print("Enter any integer number: ");
num = sc.nextInt();

/*to store maximum 32 digits of a number*/
String hexVal = "";
int dig; // to store digits
while (num > 0) {
dig = num % 16;
switch (dig) {
case 15:
hexVal += "F";
break;
case 14:
hexVal += "E";
break;
case 13:
hexVal += "D";
break;
case 12:
hexVal += "C";
break;
case 11:
hexVal += "B";
break;
case 10:
hexVal += "A";
break;
default:
hexVal += Integer.toString(dig);
}
num = num / 16;
}

for (counter = hexVal.length() - 1; counter >= 0; counter--)
System.out.print(hexVal.charAt(counter));
}
}``````

Output:

```Complie 	:	javac CovDec2Hex.java
Run		:	java CovDec2Hex
Output
Enter any integer number: 31231
79FF
```

## Using Integer.toHexString() method

``````// java program to convert decimal to hexadecimal

import java.util.*;

public class CovDec2Hex {
public static void main(String args[]) {
int num;
Scanner sc = new Scanner(System.in);

System.out.print("Enter any integer number: ");
num = sc.nextInt();

String hexVal = "";
hexVal = Integer.toHexString(num);
System.out.println("Hexadecimal Number is: " + hexVal);
}
}``````

Output:

```Complie 	:	javac CovDec2Hex.java
Run		:	java CovDec2Hex
Output
Enter any integer number: 31231
```