Introduction to JavaScript

calculator.js

// basic arithmetic calculator without a frontend
var operations = ["+", "-", "*", "/", "**", "%"]
let operation = prompt("Please enter operation");

// check if operation is valid
while (true){
    if (!(operations.includes(operation))){
        operation = prompt("Invalid operation: Enter operation again")
    }
    else {
        break;
    }
}


let number1 = prompt("Good\nEnter first number");
operation = number1 + " " + operation

let number2 = prompt(operation, "");
operation += " " + number2

// print result
alert(operation + " =\n" +eval(operation))