Java long compareTo() with examples

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The java.lang.Long.compareTo() is a built-in method in java that compares two Long objects numerically. This method returns 0 if this object is equal to the argument object, it returns less than 0 if this object is numerically less than the argument object and a value greater than 0 if this object is numerically greater than the argument object.

Syntax:

public int compareTo(Object obj)

Parameter: 
obj - The object which is to be compared to.

Returns: The function returns three values:

equal to 0: Object is equal to the argument object
less than 0: Object is less than the argument object
greater than 0: Object is greater than the argument object

Program 1: The program below demonstrates the working of function.

// Java program to demonstrate
// of java.lang.Long.compareTo() method
import java.lang.Math;
  
class Gfg1 {
  
    // driver code
    public static void main(String args[])
    {
  
        // when two objects are different
        Long obj1 = new Long(124);
        Long obj2 = new Long(167);
        int compareValue = obj1.compareTo(obj2);
  
        if (compareValue == 0)
            System.out.println("object1 and object2 are equal");
        else if (compareValue < 0)
            System.out.println("object1 is less than object2");
        else
            System.out.println("object1 is greater than object2");
    }
}

Output:

object1 is less than object2

Program 2: The program below demonstrates the working of function when no argument is passed

// Java program to demonstrate
// of java.lang.Long.compareTo() method
import java.lang.Math;
  
class Gfg1 {
  
    // driver code
    public static void main(String args[])
    {
        // when no argument is passed
        Long obj1 = new Long(124);
        Long obj2 = new Long(167);
  
        int compareValue = obj1.compareTo();
  
        if (compareValue == 0)
            System.out.println("object1 and object2 are equal");
        else if (compareValue < 0)
            System.out.println("object1 is less than object2");
        else
            System.out.println("object1 is greater than object2");
    }
}

Output:

prog.java:14: error: method compareTo in class Long cannot be applied to given types;
      int compareValue = obj1.compareTo(); 
                             ^
  required: Long
  found: no arguments
  reason: actual and formal argument lists differ in length
1 error

Program 3: The program below demonstrates the working of function when anything other than object is passed in an argument

// Java program to demonstrate
// of java.lang.Long.compareTo() method
import java.lang.Math;
  
class Gfg1 {
  
    // driver code
    public static void main(String args[])
    {
  
        // when anything other than object
        // argument is passed
        Long obj1 = new Long(124);
  
        int compareValue = obj1.compareTo("gfg");
  
        if (compareValue == 0)
            System.out.println("object1 and object2 are equal");
        else if (compareValue < 0)
            System.out.println("object1 is less than object2");
        else
            System.out.println("object1 is greater than object2");
    }
}

Output:

prog.java:14: error: incompatible types: String cannot be converted to Long
      int compareValue = obj1.compareTo("gfg"); 
                                        ^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error