Java 2 - Operators

Operators

• The operators are almost the same in Java as in other programming languages.
• Therefore if you have experience with another programming language, you will find Java operators familiar.

• Operators are used to perform operations on variables and values.
• Java has the following types of operators:
  • Arithmetic operators - used to perform arithmetic operations on variables and values
  • Assignment operators - used to assign values to variables
  • Comparison operators - used to compare two values
  • Logical operators - used to determine the logic between variables or values
  • Bitwise operators - used to perform bitwise operations
  • Ternary operators - used to evaluate a boolean expression
  • Instanceof operator - used to test if an object is an instance of a class

Arithmetic Operators

• Arithmetic operators are used to perform common mathematical operations.
• They are:
  • + - Addition
  • - - Subtraction
  • * - Multiplication
  • / - Division
  • % - Modulus
  • ++ - Increment
  • -- - Decrement

Assignment Operators

• Assignment operators are used to assign values to variables.
• They are:
  • = - Assigns values from right side operands to left side operand
  • += - It adds right operand to the left operand and assign the result to left operand
  • -= - It subtracts right operand from the left operand and assign the result to left operand
  • *= - It multiplies right operand with the left operand and assign the result to left operand
  • /= - It divides left operand with the right operand and assign the result to left operand
  • %= - It takes modulus using two operands and assign the result to left operand
  • <<= - It shifts left operand value to right by the number of bits specified by the right operand and assign the result to left operand
  • >>= - It shifts left operand value to right by the number of bits specified by the right operand and assign the result to left operand
  • &= - It performs ‘Bitwise AND’ on the operands and assign the result to left operand
  • ^= - It performs ‘Bitwise Exclusive OR’ on the operands and assign the result to left operand
  • |= - It performs ‘Bitwise Inclusive OR’ on the operands and assign the result to left operand

Comparison Operators

• Comparison operators are used to compare two values.
• They are:
  • == - Checks if the values of two operands are equal or not, if yes then condition becomes true
  • != - Checks if the values of two operands are equal or not, if values are not equal then condition becomes true
  • > - Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true
  • < - Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true
  • >= - Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true
  • <= - Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true

Comparing Strings

• You cannot use the == operator to compare two strings.
• Likewise the != operator.
• You can use the equals() method to compare two strings.

public class MyClass {
    public static void main(String[] args) {
        String txt = "Hello";
        String txt2 = "Hello";
        System.out.println(txt.equals(txt2)); // true
    }
}

• Instead of using != to compare two strings, you can use the ! operator to negate the result of the equals() method.

public class MyClass {
    public static void main(String[] args) {
        String txt = "Hello";
        String txt2 = "Hello";
        System.out.println(!txt.equals(txt2)); // false
    }
}