JavaScript notes-Application of object properties

You can simulate the map type and remove array duplicates based on the principle that key is never repeated in the JS object .

1. Analog map Type (1) construct map object

function Map () {//privatevar obj = {};//Empty object container, storing key value pairs    //put Method     This. put = function (Key,value) {Obj[key] = value; }//get Method     This. get = function (key) {if(Obj[key] | | obj[key] = = 0 | | obj[key] = = =false){returnObj[key]; }Else{return NULL; }    }//remove Method     This. remove = function (key) {if(Obj[key] | | obj[key] = = 0 | | obj[key] = = =false) {delete Obj[key]; }    }//size Method     This. Size = function () {var count= 0; for(Var arr in obj)         {count++; }returnCount }//Traversal method, using the callback function of the way     This. Eachmap = function (fn) { for(Var arr in obj)         {fn (Arr,obj[arr]); }    }}

(2) test code

//Simulate the type of map in Java New Map (); M.put (' n ', ' Sscs '); Alert (M.size ()); Alert (m.get (' 01 ')); M.remove (' 01 '); //Traverse the object element, the passed parameter is a function M.eachmap (key,value) {     alert (key + ":" +value);});

2. Remove array duplicates (1) Implementation code

function Unique (arr) {    //First step: Change the value in the array to the key    //Private Object in the JS object for    (var i = 0,j = arr.length;i<j;i++) {        true;    }    //second: Restore the JS object to an array    var arr = []; //Private Object     for (var attr in obj) {        if(Obj.hasownproperty (attr)) {            arr.push (attr);        }    }    return arr;}

(2) test procedure

var arr = [1,1,3,4,5];alert (Unique (arr)); Show 1,3,4,5

JavaScript notes-Application of object properties