Java Operators

In Java programming, operators are used to perform operations on operands (i.e. variables and values).

Java categorizes the operators in the following groups:

1. Arithmetic operators
2. Assignment operators
3. Relational operators
4. Logical operators
5. Bit-wise operators
6. Conditional Operators

1. Arithmetic Operators:

These operators are used with numeric values to perform common mathematical operations.​

Example 1

//ArithmeticOperatorsDemo.java
public class ArithmeticOperatorsDemo {

    public static void main(String[] args) {
        int a = 100;
        int b = 5;
        int c, d;
        System.out.println("ADD: " + (a+b));
        System.out.println("SUB: " + (a-b));
        System.out.println("MUL: " + (a*b));
        System.out.println("DIV: " + (a/b));
        System.out.println("MOD: " + (a%b));
        
        //post increment or decrement
        c = b++; d = b--;
        System.out.println("Post ++: " + c);
        System.out.println("Post --: " + d);
        
        //pre increment or decrement
        c = ++b; d = --b;
        System.out.println("Pre ++: " + c);
        System.out.println("Pre --: " + d);
    }
}

Output:

ADD: 105
SUB: 95
MUL: 500
DIV: 20
MOD: 0
Post ++: 5
Post --: 6
Pre ++: 6
Pre --: 5

2. Assignment Operators:

These operators are used to assign values to variables.

Example 2

//AssignmentOperatorsDemo.java
public class AssignmentOperatorsDemo {

    public static void main(String[] args) {
        int x = 5;
        x = x + 5;  //x += 5
        System.out.println("x = " + x);
        x = x - 5;  //x -= 5
        System.out.println("x = " + x);
        x = x * 5;  //x *= 5
        System.out.println("x = " + x);
        x = x / 5;  //x /= 5
        System.out.println("x = " + x);
        x = x % 5;  //x %= 5
        System.out.println("x = " + x);
    }
}

Output:

x = 10
x = 5
x = 25
x = 5
x = 0

3. Relational Operators:

These operators are used to compare two values.

Example 3

//RelationalOperatorsDemo.java
public class RelationalOperatorsDemo {

    public static void main(String[] args) {
        int a = 10, b = 5;
        System.out.println(a>b);   //true
        System.out.println(a<b);   //false
        System.out.println(a==b);  //false
        System.out.println(a!=b);  //true
        System.out.println(a>=b);  //true
        System.out.println(a<=b);  //false
    }
}

Output:

true
false
false
true
true
false

4. Logical Operators:

These operators are used to combine conditional statements.

Example 4

//LogicalOperatorsDemo.java
public class LogicalOperatorsDemo {

    public static void main(String[] args) {
        boolean result;
        result = ((10>5) && (9<7));
        System.out.println("Logical AND = " + result); //false
        result = ((10>5) || (9<7));
        System.out.println("Logical  OR = " + result); //true
        result = !(9<7);
        System.out.println("Logical NOT = " + result); //true
    }
}

Output:

Logical AND = false
Logical  OR = true
Logical NOT = true

5. Bit-wise Operators:

These operators are used to compare binary numbers.

For example, in the table below, let x = 10 (0000 1010 in binary) and y = 4 (0000 0100 in binary)

Example 5

//BitwiseOperatorsDemo.java
public class BitwiseOperatorsDemo {

    public static void main(String[] args) {
        int x = 10;
        int y = 4;
        System.out.println("Bit-wise AND: " + (x & y)); //0
        System.out.println("Bit-wise  OR: " + (x | y)); //14
        System.out.println("Bit-wise NOT: " + (~x));    //-11
        System.out.println("Bit-wise XOR: " + (x ^ y)); //14
        System.out.println("Bit-wise right shift: " + (x >> 2)); //2
        System.out.println("Bit-wise  left shift: " + (x << 2)); //40
    }
}

Output:

Bit-wise AND: 0
Bit-wise  OR: 14
Bit-wise NOT: -11
Bit-wise XOR: 14
Bit-wise right shift: 2
Bit-wise  left shift: 40

6. Conditional Operators:

The Conditional operator is the only ternary operator (operator that takes three arguments) in Java. The operator evaluates the first argument and, if true, evaluates the second argument. If the first argument evaluates to false, then the third argument is evaluated. The conditional operator is the expression equivalent of the if-else statement.

Example 6

//ConditionalOperatorsDemo.java
public class ConditionalOperatorsDemo {

    public static void main(String[] args) {
        int a = 10, b = 12;
        boolean c = a > b ? true : false;
        System.out.println("c = " + c); 
    }
}

Output:

c = false