How to Create a Simple Calculator Program using Java Programming Language?
Here we are creating Calculator Program using the Java Programming language.
This is one of the simplest program a beginner can write and understand a lot about computer programming.
The Calculator Program that we are writing here will work on two numbers and it will support Addition, Subtraction, Multiplication and Division operations.
Program Source Code : Calculator.Java
1 package calculator;
2 import java.util.Scanner;
3
4 public class Program {
5
6 public static void main(String[] args) {
7
8 char operator;
9 double num1,num2;
10 Scanner input = new Scanner(System.in);
11
12 System.out.println("Enter the Operator ( +, -, *, / )");
13 operator = input.next().charAt(0);
14
15 System.out.println("Enter the two numbers one by one");
16 num1 = input.nextDouble();
17 num2 = input.nextDouble();
18
19 input.close();
20
21 switch( operator ) {
22 case '+':
23 System.out.printf("%.2f + %.2f = %.2f", num1,num2,(num1+num2));
24 break;
25
26 case '-':
27 System.out.printf("%.2f - %.2f = %.2f", num1,num2,(num1-num2));
28 break;
29
30 case '*':
31 System.out.printf("%.2f * %.2f = %.2f", num1,num2,(num1*num2));
32 break;
33
34 case '/':
35 if( num2 != 0 )
36 System.out.printf("%.2f / %.2f = %.2f", num1,num2,(num1/num2));
37 else
38 System.out.println("Divide by Zero Situation");
39 break;
40
41 default:
42 System.out.printf("%c is an invalid operator",operator);
43 }
44 }
45 }
Program Output : Run 1
Enter the Operator ( +, -, *, / ) :
+
Enter the two Numbers one by one : 10 20
10.00 + 20.00 = 30.00
Program Output : Run 2
Enter the Operator ( +, -, *, / ) :
-
Enter the two Numbers one by one : 10 30
10.00 - 30.00 = -20.00
Program Output : Run 3
Enter the Operator ( +, -, *, / ) :
*
Enter the two Numbers one by one : 10 50
10.00 * 50.00 = 500.00
Program Output : Run 4
Enter the Operator ( +, -, *, / ) :
/
Enter the two Numbers one by one : 10 20
10.00 / 20.00 = 0.50
Program Output : Run 5
Enter the Operator ( +, -, *, / ) :
/
Enter the two Numbers one by one : 50 0
Divide by Zero situation
Program Output : Run 6
Enter the Operator ( +, -, *, / ) :
?
Enter the two Numbers one by one : 10 20
? is an invalid Operator