Kotlin – Calculator Program

Kotlin – Basic Calculator

In Kotlin, you can create a simple calculator program that performs basic arithmetic operations such as addition, subtraction, multiplication, and division. This tutorial will guide you through the process of writing a Kotlin program for a basic calculator.

Step 1: Define the Calculator Functions

Create functions for each arithmetic operation: addition, subtraction, multiplication, and division.

fun add(a: Double, b: Double): Double {
    return a + b
}

fun subtract(a: Double, b: Double): Double {
    return a - b
}

fun multiply(a: Double, b: Double): Double {
    return a * b
}

fun divide(a: Double, b: Double): Double {
    if (b == 0.0) {
        throw IllegalArgumentException("Cannot divide by zero")
    }
    return a / b
}

Step 2: Create the Calculator Function

Create a function that takes input for the operation type (addition, subtraction, multiplication, division) and two numbers, and then calls the corresponding calculator function.

fun calculate(operation: Char, a: Double, b: Double): Double {
    return when (operation) {
        '+' -> add(a, b)
        '-' -> subtract(a, b)
        '*' -> multiply(a, b)
        '/' -> divide(a, b)
        else -> throw IllegalArgumentException("Invalid operation")
    }
}

Step 3: Use the Calculator Function

Call the calculate function with the operation type (+, -, *, /) and two numbers, and print the result.

fun main() {
    val operation = '+'
    val num1 = 10.0
    val num2 = 5.0
    val result = calculate(operation, num1, num2)
    println("Result of $num1 $operation $num2 = $result")
}

Complete Kotlin Program

The following is the complete Kotlin program for a basic calculator.

Kotlin Program

fun add(a: Double, b: Double): Double {
    return a + b
}

fun subtract(a: Double, b: Double): Double {
    return a - b
}

fun multiply(a: Double, b: Double): Double {
    return a * b
}

fun divide(a: Double, b: Double): Double {
    if (b == 0.0) {
        throw IllegalArgumentException("Cannot divide by zero")
    }
    return a / b
}

fun calculate(operation: Char, a: Double, b: Double): Double {
    return when (operation) {
        '+' -> add(a, b)
        '-' -> subtract(a, b)
        '*' -> multiply(a, b)
        '/' -> divide(a, b)
        else -> throw IllegalArgumentException("Invalid operation")
    }
}

fun main() {
    val operation = '+'
    val num1 = 10.0
    val num2 = 5.0
    val result = calculate(operation, num1, num2)
    println("Result of $num1 $operation $num2 = $result")
}

Output

Result of 10.0 + 5.0 = 15.0

Summary

By following these steps and using functions for arithmetic operations, you can create a basic calculator program in Kotlin.