gfnork node.js workshop Lesson #1 JavaScript Basics

syntax, operators, loops, conditionals, functions

Transcript

3. 3 var iable = 'hello world'; iable = 5; global_var = 'hello world'; let knowledge = ''; 47 + 11; '47' + '11'; 47 + '11'; 47 + Number('11');
4. 4 var
6. 6 4 * 10 + 2; 4 * (10 + 2); var i = 3; iable += i++; iable = ++i;
8. 8 var tru = 1, fals = 0, wtf = 2; tru || fals; wtf || fals; wtf || tru; tru || wtf; var tru = 1, fals = 0, wtf = 2; tru && fals; wtf && fals; wtf && tru; tru && wtf;
9. 9 true false
10. 10 'any string'; []; { }; 1; ''; NaN; null; undefined;
11. 11 var one = 1, two = 2, two_in_words = '2'; one == two; one != two; two == two_in_words; two === two_in_words; two < one; two >= two_in_words;
13. 13 if (one) console.log('hello noob!') else console.log('wtf'); console.log(true ? 'hello noob!' : 'wtf'); var mind_twist = 'happens' && 'is annoying' ? 'with strange statements' && 'is real terror' : 'even if your skill' > 9000 || 'you work alone'; mind_twist == "is real terror" ? console.log("hello pro!") : 'wtf';
14. 14 if else if else if else
15. 15 switch (something) { case 'really interesting': alert('wow this case is really interesting!'); break; case 42: alert('ok makes sense'); break; default: alert('no specific case was evaluated -> default'); break; }
16. 16 for(var i = 0; i <= 9000; i++) console.log('power level ' + i ); var go_on = true; while( go_on ) if( Math.random()*6 >= 5 ) go_on = false; do { // interesting thing still_interesting ? continue : break; } while ( i++ < 100 );
17. 17 for while do do while
18. 18 var Story = ['this', 'is', 'a story', 'all about', 'how my code', 'got', 'flipped turned upside down']; Story[2] + Story[5] + Story[6]; var Story2 = []; Story2.push(Story[0], Story[1], Story[4], Story[5], Story[2]); console.log(Story2 = Story2.join(' ')); console.log(Story2.split(' ')); Story2.length;
19. 19 split join
20. 20 var myObject = { sayHello : function() { console.log('hello'); }, myName : ‘gfnork' }; myObject.sayHello(); console.log(myObject.myName);
22. 22 myObject.sayName = function () { console.log('my name is: ' + this.myName); }; myObject.sayName(); var testObj = { sayName: myObject.sayName }; testObj.sayName();
23. 23 this this this this this this
24. 24 var TalkTo = function(person, msg) { var text = msg + ', ' + person; console.log(text); }; TalkTo('Gfnork', 'What’s up'); var TextTo = function(person, msg) { return = msg + ', ' + person; };
25. 25 var insult = function () { console.log('idiot!') }; var praise = function () { console.log('good boy!') }; var teacher = function () { if (Math.random() < 0.5) return insult(); else return praise(); }; teacher(); teacher();
27. 27 (function () { console.log('This output will be printed once!'); })(); var teacher = function () { var reaction = Math.random() < 0.5 ? function () { console.log('idiot!') }() : function () { console.log('good boy!') }(); return reaction; };