Author: Miroslav Popovic /
@miroslavpopovic
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Srpska verzija
function test() {
var x = 1;
var y = 2;
{
var x = 10;
var y = 20;
}
console.log(x, y);
}
test();
function test() {
let x = 1;
let y = 2;
{
let x = 10;
let y = 20;
}
console.log(x, y);
}
test();
let - variable definition close to the usageconst - constant, not allowed to be changed function test() {
const PI = 3.141569;
// PI = 6; -> ERROR
console.log(PI);
}
function logName(name) {
name = name || 'Unknown';
console.log('Name: ', name);
}
logName();
logName('JavaScript');
function logName(name='Unknown') {
console.log('Name: ', name);
}
logName();
logName('JavaScript');
//function f(x=Math.random()){...};
function add(x) {
var result = x;
// arguments.forEach(...)
for (var i = 1;
i < arguments.length; i++) {
result += arguments[i];
}
return result;
}
console.log(add(1, 2, 3, 4, 5));
function add(x, ...numbers) {
var result = x;
numbers.forEach(function(y) {
result += y;
});
return result;
}
console.log(add(1, 2, 3, 4, 5));
function add(x, y, z) {
return x + y + z;
}
var numbers = [2, 4, 6];
console.log(
add.apply(null, numbers));
function add(x, y, z) {
return x + y + z;
}
let numbers = [2, 4, 6];
console.log(add(...numbers));
// Example 2
let n2 =
[1, 2, ...numbers, 7, ...[2, 3]];
console.log(n2);
// [1, 2, 2, 4, 6, 7, 2, 3]
let numbers = [10, 20];
let [a, b] = numbers;
console.log(a, b);
let position = { lat: 42.34455, lng: 17.34235 };
let {lat, lng} = position;
console.log(lat, lng);
let book = {
title: 'Lord of the Rings',
author: 'J.R.R. Tolkien',
pages: 550,
tags: ['fantasy', 'fiction'],
price: {
hardcover: 34.5,
softcover: 22.5
}
};
let {author, tags: [,tag], price: {softcover}} = book;
console.log(author, tag, softcover);
let httpPost = function(url, {
cache = true,
contentType = 'application/json',
timeout = 2500,
headers = {}
}) {
console.log(url, cache, contentType, timeout, headers);
};
httpPost('http://google.com', {
cache: false,
headers: {
Authorization: 'Bearer SOMETOKEN'
}
});
var firstName = 'Miroslav',
lastName = 'Popovic';
var fullName =
firstName + ' ' + lastName;
console.log(fullName);
var add = function(x, y) {
return x + ' + ' + y +
' = ' + (x+y);
};
console.log(add(10, 5));
console.log('Multiple lines\n' +
'with plus operator');
let firstName = 'Miroslav',
lastName = 'Popovic';
let fullName =
`${firstName} ${lastName}`;
console.log(fullName);
let add = function(x, y) {
return `${x} + ${y} = ${x+y}`;
};
console.log(add(10, 5));
console.log(`Support for
multiple lines with backticks`);
var obj = {
// defining prototype on object creation
__proto__: theProtoObj,
// shortcut for ‘handler: handler’
handler,
// shortcut for methods - 'toString: function() {}'
toString() {
// base class method call with 'super'
return 'd ' + super.toString();
},
// dynamic property names
[ 'prop_' + (() => 42)() ]: 42
};
var square = function(x) {
return x * x;
};
var add = function(x, y) {
return x + y;
};
var total = function() {
return square(add(5, 3));
};
console.log('5 * 5 = ', square(5));
console.log('2 + 3 = ', add(2, 3));
console.log(
'(5 + 3)*(5 + 3) = ', total());
let square = x => x * x;
let add = (x, y) => x + y;
let total = () => square(add(5,3));
console.log('5 * 5 = ', square(5));
console.log('2 + 3 = ', add(2, 3));
console.log(
'(5 + 3)*(5 + 3) = ', total());
var add = function(x, y) {
var result = x + y;
return result;
};
console.log('2 + 3 = ', add(2, 3));
let add = (x, y) => {
let result = x + y;
return result;
};
console.log('2 + 3 = ', add(2, 3));
var obj = {
index: 1,
loadData: function() {
var self = this;
$.get('http://ip.jsontest.com')
.then(function(data) {
console.log(
'IP: ' + data.ip,
'Index: ' + self.index)
});
}
};
obj.loadData();
let obj = {
index: 1,
loadData: function() {
$.get('http://ip.jsontest.com')
.then((data) => {
console.log(
'IP: ' + data.ip,
'Index: ' + this.index)
});
}
};
obj.loadData();
function timeout(duration = 0) {
return new Promise((resolve, reject) => {
setTimeout(resolve, duration);
});
}
var p = timeout(1000).then(() => {
return timeout(2000);
}).then(() => {
throw new Error("hmm");
}).catch(err => {
return Promise.all([timeout(100), timeout(200)]);
});
function Car(data) {
this.model = data.model;
this.year = data.year;
this.wheels = data.wheels || 4;
}
Car.prototype.drive = function() {
console.log(
'Driving ' + this.model);
}
var yugo = new Car({
model: 'Yugo 55', year: 1985 });
yugo.drive();
class Car {
constructor (data) {
this.model = data.model;
this.year = data.year;
this.wheels = data.wheels || 4;
}
drive() {
console.log(
'Driving ' + this.model);
}
}
let yugo = new Car({
model: 'Yugo 55', year: 1985 });
yugo.drive();
class Car {
constructor ({model, year, wheels=4}) {
this.model = model; this.year = year; this.wheels = wheels;
}
get isNew() { return this._isNew; }
set isNew(value) { this._isNew = value; }
drive() {
console.log(`Driving ${this.model}`); this.isNew = false;
}
}
let yugo = new Car({ model: 'Yugo 55', year: 1985 });
yugo.drive();
console.log(yugo.isNew);
class Car { ... }
class Truck extends Car {
constructor ({model, year, wheels=6}) {
super({model, year, wheels});
}
drive () {
super.drive();
console.log(`Driving like a boss with ${this.wheels} wheels`);
}
}
let actros = new Truck({ model: 'Actros', year: 2005 });
actros.drive();
function Car(data) {
// ...
}
Car.drive = function(data) {
console.log('Driving...');
}
//var yugo = new Car({
// model: 'Yugo 55', year: 1985 });
//yugo.drive();
Car.drive({ road: 'autobahn' });
class Car {
// ...
static drive(data) {
console.log('Driving...');
}
}
//let yugo = new Car({
// model: 'Yugo 55', year: 1985 });
//yugo.drive();
Car.drive({ road: 'autobahn' });
// lib/math.js
export function sum(x, y) {
return x + y;
}
export var pi = 3.141593;
// app.js
import * as math from "lib/math";
alert("2π = " + math.sum(math.pi, math.pi));
// otherApp.js
import {sum, pi} from "lib/math";
alert("2π = " + sum(pi, pi));
System.import('some_module')
.then(some_module => {
// Use some_module
})
.catch(error => {
//...
});
System is a default loaderupper`${firstName} ${lastName}`0b111110111, 0o767 = 503Math, Array, Object, Number, StringSet, WeakSet, Map, WeakMap - data structureslet n = function*() { yield 1; yield 2; }Object.observe()async/await