ECMAScript 5: Новое в JavaScript

ECMAScript 5: Новое в JavaScript

• 1.
  ECMAScript 5: Новоев JavaScript Юрій Чайковський [email_address]
• 2.
  Syntax Reserved words var label = { class : " active " } Comma var fibonacci = [0, 1, 2, 3, 5, ]; Line breaks var literal = "Line breaks \ is standardized";
• 3.
  Arrays Iterations forEach(), every(), some(), map(), filter(), reduce(), reduceRight(), Search indexOf(), lastIndexOf() Type check fibonacci.isArray() === true ;
• 4.
  JSON var event = { title : " HTML5Camp ", date : new Date(" 2011-03-28T10:00:00.000Z "), } JSON.stringify(value, replacer, space) var str = JSON.stringify(event) ; {"title":"HTML5Camp","date":"2011-03-28T10:00:00.000Z"} JSON.parse(string, reviver) JSON.parse(str, function(key, value){ if (key == "title"){ return value.trim(); } });
• 5.
  Strict mode "usestrict"; location = " http://www.microsoft.com "; var person = {"name" : "Yura", "name" : "Chaikovsky"}; var geval = eval; with, arguments.caller, arguments.callee ( function (){...}).call( null ); ( function (){ return !this; })(); Function.prototype.bind(thisArg, arg1, arg2....)
• 6.
  Objects: Point function Point(x, y) {   this .x = +x; this .y = +y; } var pt = new Point(3,5); pt.x = 'foo';
• 7.
  Objects: Creating Object.create(p ,{ ( n : attrs )* })   .defineProperty( o , n , attrs ) .defineProperties( o ,{ ( n : attrs )* }) .getOwnPropertyNames( o ) -> names .getOwnPropertyDescriptor( o , n ) -> attrs attrs ::= { value: v , writable: b ,       enumerable: b , configurable: b } | { get: f()->v , set: f(v) ,      enumerable: b , configurable: b }
• 8.
  Objects: New Pointfunction Point(x, y) { return Object.freeze ({ x: +x, y: +y }); } // (new Point(3,4) instanceof Point) === false
• 9.
  Objects: New Pointfunction Point(x, y) { return Object.freeze ({ x: +x, y: +y }); } // (new Point(3,4) instanceof Point) === false function Point(x, y) { return Object.freeze( Object.create (Point.prototype, { x: { value: +x, enumerable: true }, y: { value: +y, enumerable: true } })); }
• 10.
  Objects: Accessor (getter/setter) Old school... var evnt = ( function (){ var eventType = " barcamp "; return { type : function (tp){ if (typeof tp != " undefined "){ //setter... eventType = tp; }else{ //getter... return eventType; } } }; })();
• 11.
  Objects: Creating Object.create(p ,{ ( n : attrs )* })   .defineProperty( o , n , attrs ) .defineProperties( o ,{ ( n : attrs )* }) .getOwnPropertyNames( o ) -> names .getOwnPropertyDescriptor( o , n ) -> attrs attrs ::= { value: v , writable: b ,       enumerable: b , configurable: b } | { get: f()->v , set: f(v) ,      enumerable: b , configurable: b }
• 12.
  Objects: Accessor (getter/setter) Brand new... var evnt = { eventType : "barcamp", get type(){ //getter... return evnt.eventType; }, set type(tp){ //setter... evnt.eventType = tp; } };
• 13.
  Objects: Accessor (getter/setter) or... var evnt = Object.defineProperties({}, { 'typeName' : { value : "barcamp", }, 'type' : { get : function() { return …; }, set : function(tp) { … }, } });
• 14.
  Objects: Restrictions Object.preventExtensions( obj ) Object.isExtensible( obj ) Object.seal( obj ) Object.isSealed( obj ) Object.freeze( obj ) Object.isFrozen( obj )
• 15.
  References Mark Millerhttp://www.youtube.com/watch?v=Kq4FpMe6cRs Douglas Crockford http://www.slideshare.net/douglascrockford/newandimproved Ilia Kantor http://www.youtube.com/watch?v=082iuEKV72c John Resig http://ejohn.org/blog/ecmascript-5-objects-and-properties/ http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/ David Flanagan http://davidflanagan.com/Talks/es5/slides.html