Java Integer Compare Method

Integer compare() Method

The compare() method in the Integer class is a part of the Java interface and is used to compare two integers. It provides a way to compare two Integer objects or primitive int values and determine their relative ordering. This method is particularly useful when sorting or working with collections that involve integer values.

Syntax

public static int compare(int x, int y);

• x: The first integer to be compared.
• y: The second integer to be compared.

Return Value

The compare() method returns an integer value that represents the comparison result ?

• Negative value (less than 0): If x is less than y.
  
• Zero (0): If x is equal to y.
  
• Positive value (greater than 0): If x is greater than y.

Comparing Two Integer Values

The compare() method can be used to compare two integer values easily. It returns a value that indicates whether the first integer is less than, equal to, or greater than the second integer. This is particularly useful when you need to perform comparisons for sorting or ordering operations.

At first, declare int values to be compared ?

int val1 = 200;
int val2 = 250;
int val3 = 200;

Now, compare the values ?

System.out.println(Integer.compare(val1, val2));
System.out.println(Integer.compare(val1, val3));

Example

Below is an example to implement the compare() method in Java ?

public class Main {
   public static void main(String[] args) {
      int val1 = 200;
      int val2 = 250;
      int val3 = 200;
      System.out.println(Integer.compare(val1, val2));
      System.out.println(Integer.compare(val1, val3));
   }
}

Output

-1
0

Using compare() with Collections (Sorting Integers)

In addition to direct comparisons, the compare() method is highly effective in sorting operations. We can use it with Java collections, such as lists, to sort integer values based on their natural order. This can be done efficiently using the Collections.sort() method in combination with Integer.compare().

Sorting using compare() in a custom comparator ?

Collections.sort(numbers, (a, b) -> Integer.compare(a, b));

Example

Below is an example to implement the compare() method in Java using collections?

import java.util.*;

public class IntegerCompareSortingExample {
   public static void main(String[] args) {
      List<Integer> numbers = Arrays.asList(50, 20, 30, 10, 40);

      Collections.sort(numbers, (a, b) -> Integer.compare(a, b));
      
      System.out.println("Sorted List: " + numbers);
   }
}

Output

Sorted List: [10, 20, 30, 40, 50]

Conclusion

The Integer.compare() method is a simple and effective way to compare integers in Java. It is especially useful in sorting and when working with collections. The method provides clear results: a negative value if the first integer is smaller, zero if they are equal, and a positive value if the first integer is greater.