henryspivey

/**
 * Write a function to determine if a number is an integer
 */

let isInt = function (num) {
    return (!isNaN(num) && parseInt(num) === num)    
}
console.log(3, isInt(3));
console.log(3.5, isInt(3.5));
console.log(1.00000, isInt(1.00000));

henryspivey

// Using `this` inside an object
// The object has functions created three different ways 
// What will be the result of the three log statements?

const circle = {
    radius: 10,
    circumference: function () {
        return (2 * Math.PI * this.radius);
    },
    diameter() {

henryspivey

//Why do we get this weird result from the map method?
// myarray.map(func);
//We want to convert 3 strings into numbers

let result = ['1', '7', '11'].map(parseInt); //returns [1, NaN, 3]
// solution
['1', '7', '11'].map(item => parseInt(item))
console.log(result);

henryspivey

// Generate Random Hex Colour Values

/*
use Math.random


*/


function colour() {    

henryspivey

//var hoisting vs let hoisting
//WHAT will be the output from this code and why?

function f() {
    console.log('var', area); // undefined
    if(area !== 'undefined) {
       console.log('var', area);
    }
    console.log('let', name); // reference error
    try {

henryspivey

//version 1
let a1 = Array.from({
    length: 5
}, n => Math.random());
console.log('1', a1);

//version 2
let a2 = new Array(5).fill(1).map(n => Math.random());
console.log('2', a2);

henryspivey

function f1(a) {
    let b = 2;
    setTimeout(function () {
        console.log(a, b)
    }, 1000);
}
// has a problem
// use let to scope variable inside for curly braces
function f2() {
    for (var i = 0; i < 3; i++) {

henryspivey

/**
 * Create an example of a JavaScript Singleton.
 * After the first object is created, it will return additional 
 * references to itself
 */

let obj = (function () {
    let objInstance; //private variable
    function create() { //private function to create methods and properties
        let _isRunning = false;

henryspivey

.directive('backButton', ['$ionicHistory',function($ionicHistory){
    return {
        restrict: 'E',
        template: "<button class='button button-clear' id='customBackButton'><i class='button-icon icon ion-ios-arrow-left'></i> Back</button>",
        link: function($scope, element, attrs) {
            element.bind('click', function(){
               $ionicHistory.goBack();
            })
        }
    }