Given a number of int datatype in Java, your task is to write a Java program to convert this given int datatype into a long datatype.
Example:
Input: intnum = 5 Output: longnum = 5 Input: intnum = 56 Output: longnum = 56
Int is a smaller data type than long. Int is a 32-bit integer while long is a 64-bit integer. They both are primitive data types and the usage depends on how large the number is.
Java int can be converted to long in two simple ways:
- Using a simple assignment. This is known as implicit type casting or type promotion, the compiler automatically converts smaller data types to larger data types.
- Using valueOf() method of the Long wrapper class in java which converts int to long.
- In this, we are simply assigning an integer data type to a long data type.
- Since integer is a smaller data type compared to long, the compiler automatically converts int to long, this is known as Implicit type casting or type promotion.
Java
// Java program to demonstrate// use of implicit type castingÂ
import java.io.*;import java.util.*;class GFG {Â Â Â Â public static void main(String[] args)Â Â Â Â {Â Â Â Â Â Â Â Â int intnum = 5;Â
        // Implicit type casting , automatic        // type conversion by compiler        long longnum = intnum;Â
        // printing the data-type of longnum        System.out.println(            "Converted type : "            + ((Object)longnum).getClass().getName());Â
        System.out.println("After converting into long:");        System.out.println(longnum);    }} |
Output
Converted type : java.lang.Long After converting into long: 5
2. Â Long.valueOf() method:
- In this, we are converting int to long using the valueOf() method of the Long Wrapper class.
- The valueOf() method accepts an integer as an argument and returns a long value after the conversion.
Java
// Java program to convert// int to long using valueOf() methodÂ
import java.io.*;Â
class GFG {Â Â Â Â public static void main(String[] args)Â Â Â Â {Â Â Â Â Â Â Â Â int intnum = 56;Â Â Â Â Â Â Â Â Long longnum = Long.valueOf(intnum);Â
        // printing the datatype to        // show longnum is of type        // long contains data of intnum        System.out.println(            "Converted type : "            + ((Object)longnum).getClass().getName());Â
        // accepts integer and        // returns a long value        System.out.println("After converting into long:"                           + "\n" + longnum);    }} |
Output
Converted type : java.lang.Long After converting into long: 56
