JavaScript Learning Notes (ii)

= = = Scope ======var color = "Blue";/*function ChangeColor () {if (color== "blue") {color = "red";} Else{color= "Yellow";}} ChangeColor (); alert ("Color is now" +color);//Output Color is now Red*///====object type ======//One, there are two ways to create an object instance. The first is the use of the new operator followed by the object constructor/*var person = new Object ();p erson.name = "Yoyo";p erson.age = 24;alert (json.stringify (person ); *///the second is to use the object literal variable notation/*var person = {name: ' YY ', Age:29};*///alert (json.stringify (person)),//alert (person.name);// Alert (person["name"]);//==== object literal ======/*function displayinfo (args) {var output = ""; if (typeof args.name = = "string") { Output + = "Name:" + args.name + "\ n";} if (typeof args.age== "number") {output+= "Age:" +args.age+ "\ n";} alert (output);} DisplayInfo ({name: "YY", age:24}); DisplayInfo ({name: "Yoyo"}), *///========array=========var colors = ["Red", "Blue", "Green"];//alert (colors[3]); Colors[2]= "BLACK"; colors[4]= "Brown"; When larger than the array length, it is automatically added to the array, length plus 1.//alert (colors),//if (colors instanceof Array) {//instanceof array to determine if an object is not an array//alert (" Colors is an Array. "); /}//======1.arrayobject.join (separator) ====alert (Colors.join ("-")); If an item is null or undefined, the value is represented as an empty string in the results returned by the join (), tolocalestring (), toString (), and valueof () methods.

= = = Stack method ====var colors = new Array (), var count = Colors.push ("Red", "green");//alert (count); ->2//alert (colors); Red,greencount = Colors.push ("BLACK"); alert (colors.length); ->3alert (count); ->3var item = Colors.pop (); alert (item); ->blackalert (colors.length); ->2

　　

JavaScript Learning Notes (ii)