Comparison or Relational Operators in Java

Comparison or Relational operators in Java are used to compare two values and determine if they are equal, greater than, or less than each other.

List of comparison operators in Java

== Operator

This operator is used to determine if two values are equal to each other. For example:

int a = 5;
int b = 5;
if (a == b) {
  System.out.println("a and b are equal");
}

!= Operator

This operator is used to determine if two values are not equal to each other. For example:

int a = 5;
int b = 6;
if (a != b) {
  System.out.println("a and b are not equal");
}

> Operator

This operator is used to determine if one value is greater than another. For example:

int a = 5;
int b = 6;
if (a > b) {
  System.out.println("a is greater than b");
}

< Operator

This operator is used to determine if one value is less than another. For example:

int a = 5;
int b = 6;
if (a < b) {
  System.out.println("a is less than b");
}

>= Operator

This operator is used to determine if one value is greater than or equal to another. For example:

int a = 5;
int b = 5;
if (a >= b) {
  System.out.println("a is greater than or equal to b");
}

<= Operator

This operator is used to determine if one value is less than or equal to another. For example:

int a = 5;
int b = 5;
if (a <= b) {
  System.out.println("a is less than or equal to b");
}

Example

public class Test {
    public static void main(String[] args) {
        int a = 10;
        int b = 5;
        boolean x = true;
        boolean y = false;
        boolean result;

        // Integer comparisons
        result = (a == b);
        System.out.println(a + " == " + b + " : " + result); // Output: 10 == 5 : false

        result = (a != b);
        System.out.println(a + " != " + b + " : " + result); // Output: 10 != 5 : true

        result = (a > b);
        System.out.println(a + " > " + b + " : " + result);  // Output: 10 > 5 : true

        result = (a < b);
        System.out.println(a + " < " + b + " : " + result);  // Output: 10 < 5 : false

        result = (a >= b);
        System.out.println(a + " >= " + b + " : " + result); // Output: 10 >= 5 : true

        result = (a <= b);
        System.out.println(a + " <= " + b + " : " + result); // Output: 10 <= 5 : false

        // Boolean comparisons
        result = (x == y);
        System.out.println(x + " == " + y + " : " + result); // Output: true == false : false

        result = (x != y);
        System.out.println(x + " != " + y + " : " + result); // Output: true != false : true
    }
}

Output

10 == 5 : false
10 != 5 : true
10 > 5 : true
10 < 5 : false
10 >= 5 : true
10 <= 5 : false
true == false : false
true != false : true

It is important to note that comparison operators can only be used with certain data types, such as int, double, char, and boolean. They cannot be used with reference types, like String. To compare strings in Java, you can use the .equals() method. For example:

String str1 = "Hello";
String str2 = "Hello";
if (str1.equals(str2)) {
  System.out.println("str1 and str2 are equal");
}

Comparison operators are a fundamental part of programming and are used in many different contexts, including decision making and looping. Understanding how to use these operators is an essential skill for any Java programmer.