This example shows the importance of Javascript hoisting.

scope-hoisting.js

let result = 1;

// here this declaration must come first before using it
// it is a function variable declaration so it should be declared before its usage
const addNumber = function (numToAdd) {
    result = result + numToAdd;
    return result;
}


console.log(addNumber(3));  // outputs 4
console.log(result);    // outputs 4

// function addNumber(numToAdd) {
//     result = result + numToAdd;
//     return result;
// }