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Java Program to Convert Long to String
  • Difficulty Level : Expert
  • Last Updated : 27 Nov, 2020

Conversion of long type to string type generally comes in need in the case when we have to display a long number in GUI application because everything is displayed as string form.

Given a Long number, the task is to convert it into String in Java.

Examples:

Input:Long = 20L
Output:"20"

Input:Long = 999999999999L
Output:"999999999999"

A. Using + operator

For converting any data-type to string type, we can simply add/+ empty string indicated by double quotes(“”).

Syntax:



String str = l+" ";

Java




// Java program to convert Long to String  
// using + operator 
      
public class GFG {  
      
    // main method  
    public static void main(String args[])  
    {  
      
        // create a Long  
        Long varLong = 999999999999L;  
      
        // convert into String 
        String str = varLong+" "
        
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "+str.getClass().getName());
      
        // print Long as String  
        System.out.println(str);  
    }  
}
Output
Converted type : java.lang.String
999999999999

B. Using String.valueOf()

The valueOf() method converts data from its internal form into human-readable form. It is a static method that is overloaded within a string for all of Java’s built-in types so that each type can be converted properly into a string.

It is called when a string representation of some other type of data is needed-for example during concatenation operation. You can call this method with any data type and get a reasonable String representation.

Syntax:

String str = String.valueOf(varLong);

Java




// Java program to convert Long to String
// using valueOf() Method
  
public class GFG {
  
    // main method
    public static void main(String args[])
    {
  
        // create a Long
        Long varLong = 999999999999L;
  
        // convert into String
        String str = String.valueOf(varLong);
  
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "
                           + str.getClass().getName());
  
        // print Long as String
        System.out.println(str);
    }
}
Output
Converted type : java.lang.String
999999999999

C. Using Long.toString()

Object class contains toString() method. We can use toString() method to get string representation of an object. Whenever we try to print the Object reference then internally toString() method is invoked. If we did not define toString() method in your class then Object class toString() method is invoked otherwise our implemented/Overridden toString() method will be called.

Syntax:

String str = Long.toString(varLong);

Java




// Java program to convert Long to String  
// using toString() method
      
public class GFG {  
      
    // main method  
    public static void main(String args[])  
    {  
      
        // create a Long  
        Long varLong = 999999999999L;  
      
        // convert into String 
        String str = Long.toString(varLong);  
      
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "
                           + str.getClass().getName());
        
        // print Long as String  
        System.out.println(str);  
    }  
}
Output



Converted type : java.lang.String
999999999999

D. new Long(long l)

This constructer is not vald in java 9.

Syntax:

String str = new Long(varLong).toString();

Java




// Java program to convert Long to String  
// using long constructer  
   
import java.util.*;
public class GFG {  
      
    // main method  
    public static void main(String args[])  
    {  
      
        // create a Long  
        Long varLong = 999999999999L;  
      
        // convert into String 
        String str = new Long(varLong).toString();  
      
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "
                           + str.getClass().getName());
        
        // print Long as String  
        System.out.println(str);  
    }  
}

Since this version of java does not support this constructor. Hence, on running the program, we will get the error displaying

Note: prog.java uses or overrides a deprecated API.

E. Using String.format()

The java string format() method returns a formatted string using the given locale, specified format string and arguments.

Syntax:

long varLong = 9999999L;
String str = String.format("%d", varLong);

Java




// Java program to demonstrate
// working of format() method
  
class Gfg {
    
    public static void main(String args[])
    {
        long varLong = 9999999L;
  
        String str = String.format("%d", varLong);
  
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "
                           + str.getClass().getName());
  
        // print Long as String
        System.out.println(str);
    }
}
Output
Converted type : java.lang.String
9999999

F. Using StringBuilder, StringBuffer object

StringBuffer is a peer class of String that provides much of the functionality of strings. The string represents fixed-length, immutable character sequences while StringBuffer represents growable and writable character sequences.

Syntax:

long varLong = 9999999L;
String str = new StringBuilder().append(varLong).toString();

Java




// Java program to convert long to
// string using StringBuilder
  
class Gfg {
    public static void main(String args[])
    {
        long varLong = 9999999L;
  
        String str = new StringBuilder().append(varLong).toString();
  
        // printing the type of str to
        // show that long has been converted to string
        System.out.println("Converted type : "
                           + str.getClass().getName());
  
        // print Long as String
        System.out.println(str);
    }
}
Output
Converted type : java.lang.String
9999999

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