JS Fundamentals - Common Truthy bug

by smichelotti

JavaScript

function multiplyByTwo(num) {
    //if (num){
    if (num !== undefined){
        var result = num * 2;
        console.log("Answer: " + result);
    } else {
        console.log("Please provide a number.");
    }
}

multiplyByTwo(4);
multiplyByTwo(0);
multiplyByTwo();