Practical Examples

Collection of practical examples in JARU to help you get started with the language.

Hello World

The most basic example to get started:

println("Hello World!")

Basic Calculator

A simple calculator with basic operations:

func calculator(a, b, operation)
    switch (operation)
        case "+":
            return a + b
        case "-":
            return a - b
        case "*":
            return a * b
        case "/":
            if (b != 0) then
                return a / b
            else
                return "Error: Division by zero"
            end
        default:
            return "Invalid operation"
    end
end

println(calculator(10, 5, "+"))  // 15
println(calculator(10, 5, "-"))  // 5
println(calculator(10, 5, "*"))  // 50
println(calculator(10, 5, "/"))  // 2

LED Control (ESP32)

Example of how to control an LED with GPIO:

use GPIO

// Configure pin 2 as output (built-in LED on many ESP32)
GPIO.pin(2, GPIO.OUTPUT)

// Blink the LED
while (true)
    GPIO.write(GPIO.HIGH)
    pause(1000)
    GPIO.write(GPIO.LOW)
    pause(1000)
end

Sensor Reading

Example of reading an analog sensor:

use GPIO

GPIO.pin(34, GPIO.INPUT)

while (true)
    var value = GPIO.analogRead(sensor)
    println("Sensor value: ", value)
    pause(500)
end

Using Classes

Example of object-oriented programming:

class Vehicle
    def init(brand, model)
        this.brand = brand
        this.model = model
        this.running = false
    end
    
    def start()
        this.running = true
        println(this.brand, " ", this.model, " started")
    end
    
    def stop()
        this.running = false
        println(this.brand, " ", this.model, " stopped")
    end
end

class Car : Vehicle
    def init(brand, model, doors)
        this.brand = brand
        this.model = model
        this.doors = doors
        this.running = false
    end
    
    def info()
        println("Car: ", this.brand, " ", this.model)
        println("Doors: ", this.doors)
    end
end

var myCar = Car("Toyota", "Corolla", 4)
myCar.info()
myCar.start()

List Handling

Example of working with lists:

var fruits = ["apple", "pear", "orange"]

// Add element
fruits.append("banana")

// Iterate through the list
foreach (var fruit in fruits)
    println(fruit)
end

// Access by index
println("First fruit: ", fruits[0])

Recursive Fibonacci

Example of recursion calculating Fibonacci numbers:

func fibonacci(n)
    if (n <= 1) then
        return n
    else
        return fibonacci(n - 1) + fibonacci(n - 2)
    end
end

for (var i = 0; i < 10; i++)
    print(fibonacci(i), " ")
end
// Output: 0 1 1 2 3 5 8 13 21 34