Day 5: Understanding Java Operators

Source: Dev.to

What is an Operator in Java?

In Java, an operator is a special symbol or keyword used to perform operations such as:

• Addition
• Subtraction
• Division
• Comparison
• Logical checking

Important terms

• Operator – Symbol that performs an operation
• Operand – Value on which the operator works

Example

int a = 10;

• = is the operator
• a and 10 are operands

Types of Operators in Java

Assignment Operator

Used to assign a value to a variable.

int no = 10;

Arithmetic Operators

Used to perform mathematical calculations.

Examples

int a = 10;
int b = 3;

System.out.println(a + b); // Addition
System.out.println(a - b); // Subtraction
System.out.println(a * b); // Multiplication
System.out.println(a / b); // Division
System.out.println(a % b); // Modulus

Unary Operators

Unary operators work on a single variable.

Increment (++)

• Post‑increment (no++) – Use the value first, then increase it.

  int no = 10;
  System.out.println(no++); // 10
  System.out.println(no);    // 11

• Pre‑increment (++no) – Increase the value first, then use it.

  int age = 15;
  System.out.println(++age); // 16

Decrement (--)

• Post‑decrement (no--) – Use the value first, then decrease it.

  int no = 10;
  System.out.println(no--); // 10
  System.out.println(no);    // 9

• Pre‑decrement (--no) – Decrease the value first, then use it.

  int age = 15;
  System.out.println(--age); // 14

Equality and Relational Operators

Used to compare two values.

Examples

int a = 10;
int b = 20;

System.out.println(a == b); // false
System.out.println(a != b); // true
System.out.println(a  18 && age < 60); // true