Arithmetic operators

Introduction to Java

Jim White

Java Developer

Operators

Working with, modifying variables
- Performing calculations
- Changing values
- Comparing values
Operators: built-in symbols for various tasks
Arithmetic operators

Code operations on variables, including calculations, comparisons, and changing values

Addition using +

public class Main {
    public static void main(String[] args) {
        // Assign calculation to variable a
        int a = 5 + 6;
        // Print the value of a
        System.out.println(a);  
    }
}

Addition using +

// Adding doubles
double x = 5.5;
double y = 4;

double xPlusY = x + y; // Value is 9.5


// String concatenation
String message = "Hello";
String messageForJim = message + " Jim"; // Value is "Hello Jim"

Increment using ++

Use ++ to raise value by 1

int age = 30;

// Using increment to add 1
age++; // Value is now 31

Subtraction using -

// Subtract

double productPrice = 99.9;

productPrice = productPrice - 10; // Value is now 89.9


// Decrement value
int productLaunch = 99;

productLaunch--; // Values is now 98

Multiply using *

int price = 100;
int quantity = 1;

// Multiply two integers
int orderRevenue = newPrice * quantity; // Value is 100, int


double newPrice = 94.9;
int quantity = 1;

// Multiply with double
double newOrderRevenue = newPrice * quantity; // Value is 94.9, double

Division using /

class IntDivision {
  public static void main (String[] args){

    int numOrders = 100;
    int days = 30;

    // Output is 3,
    // because both numbers are integers
    System.out.println(numOrders/days); 
  }
}

class DoubleDivision {
  public static void main (String[] args){
    int numOrders = 100;
    int days = 30;

    // Either assing to double
    double avgOrders = numOrders / days;
    System.out.println(avgOrders); 

    // Or use a double in the division
    System.out.println(numOrders/30.0); 
...

3.3333333333333335
3.3333333333333335

Division using /

class IntDivision {
  public static void main (String[] args){
    int numOrders = 100;
    int days = 30;
    // Output is 3,
    // because both numbers are integers
    System.out.println(numOrders / days); 
  }
}

Division using /

class DoubleDivision {
  public static void main (String[] args){
    int numOrders = 100;
    int days = 30;
    // Either assing to double
    double avgOrders = numOrders / days;
    System.out.println(avgOrders); 
    // Or use a double in the division
    System.out.println(numOrders / 30.0); 
  }
}

3.3333333333333335

Recap

Operation	Operator	Example
Addition	`+`	`5 + 1.5`
Subtraction	`-`	`3.6 - 2`
Multiplication	`*`	`0.3 * 2`
Division	`/`	`59 / 4`

Division of two ints returns an int, unless assigned to double
Division with at least one double returns a double

Let's practice!

Introduction to Java