Advanced programming practices for arrays in JavaScript-2

let's see . EcmaScript5 The array of new APIs in the specification, they are very useful,

In the end of this section, we will use array array as an object to construct a ArrayList class similar to that in Java.

To facilitate the encapsulation of common logic for code reuse.

Api:

/** @param {function} callback@param {Object} [InitialValue] @return {object}*/array.prototype.reduce = function ( Callback,initialvalue) {};/** @param {Function} callback@param {Object} [InitialValue] @return {object}*/ Array.prototype.reduceRight = function (callback,initialvalue) {};/** @param {Object} searchelement@param {Number} [ FromIndex] @return {number}*/array.prototype.indexof = function (searchelement,fromindex) {};/** @param {Object} Searchelement@param {Number} [FromIndex] @return {number}*/array.prototype.lastindexof = function (Searchelement, FromIndex) {};/** @param {Function} callback@param {Object} [Thisobject] @return {boolean}*/array.prototype.every = function (callback,thisobject) {};/** @param {Function} callback@param {Object} [Thisobject] @return {array}*/ Array.prototype.filter = function (callback,thisobject) {};/** @param {function} callback@param {Object} [thisobject]@ return {Void}*/array.prototype.foreach = function (callback,thisobject) {};/** @param {function} callback@param {OBJECT} [Thisobject] @return {array}*/array.prototype.map = function (callback,thisobject) {};/** @param {function} Callback@param {Object} [Thisobject] @return {boolean}*/array.prototype.some = function (callback,thisobject) {};/**@ param {Object} object@return {Boolean}*/array.prototype.isarray = function (object) {};

Use:

/** * @class MyEcmaScript5 * @description * @time 2014-09-16 21:38 * @author Starzou **///defines an array that stores elements of different data types var array = [8, 2 , 1, 5], array2 = [[0, 1], [1, 2], [2, 3]], value;///Array.prototype.reduce = function (ca  Llback,initialvalue) {};//dissolve array://Call the reduce method to provide a callback function,//Call the array of lenght-1 times callback function//First time previousvalue for initialvalue//thereafter The return value of the reduce method, as previousvalue//Reduceright, begins at the far right of the array, with the elements in the above//array Added value = Array.reduce (function (Previousvalue,    CurrentValue, index, array) {return previousvalue + CurrentValue;  }); Console.log (value); 16//array Flattening value = array2.reduce (function (Previousvalue, CurrentValue, index, array) {return Previousvalue.conc    at (CurrentValue); }); Console.log (value); [0, 1, 1, 2, 2, 3]///Array.prototype.indexOf = function (searchelement,fromindex) {};//looking backwards from the FromIndex index Searcheleme The NT element finds and returns its index, otherwise returns -1//fromIndex default to 0console.log (Array.indexof (1)); 2console.log (Array.indexof (3)); -1///Array.prototype. lastIndexOf = function (searchelement,fromindex) {};//looks forward from the FromIndex index to the searchelement element to find and return its index, otherwise returns -1console.log ( Array.lastindexof (1)); 2console.log (Array.lastindexof (3)); -1///Array.prototype.every = function (callback,thisobject) {};//All elements of the test array have passed the test of the specified function = Array.every ( function (element, index, array) {return element > 1;}); Console.log (value); false///Array.prototype.filter = function (callback,thisobject) {};//array filter://Returns the element tested by the function (when the callback function returns True, indicating that the element passed the test), Generate a new array value = Array.filter (function (element, index, array) {return element > 1;}); Console.log (value);//[8, 2, 5]///Array.prototype.forEach = function (callback,thisobject) {};//Executes the callback function once for each array element. Array.foreach (function (element, index, array) {Console.log (element);}); Array.prototype.map = function (callback,thisobject) {};//array mapping://Returns a new array consisting of the return values of each element in the original array that are called after a specified method. Value = Array.map (function (element, index, array) {return element * element;}); Console.log (value); [64, 4, 1, 25]///Array.prototype.some = function (callback,thisobject) {};//tests whether certain elements in the array have passed the specified function. Value = Array.some (function (element, index, array) {return element > 1;}); Console.log (value); true///Array.prototype.isArray = function (object) {};//Determines whether an element is an array type Console.log (Array.isarray (Array));//True

Operation Result:

Advanced programming practices for arrays in JavaScript-2