4.4 KiB
4.4 KiB
id | title | challengeType | videoUrl | localeTitle |
---|---|---|---|---|
8d5823c8c441eddfaeb5bdef | Create a Map Data Structure | 1 | 创建地图数据结构 |
Description
Map
对象作为JavaScript object
的包装器。在Map对象上创建以下方法和操作: -
add
接受要添加到地图的key, value
对。 -
remove
接受一个键并删除关联的key, value
对 -
get
接受一个key
并返回存储的value
- 如果密钥存在
has
接受key
并返回true,否则返回false 。 -
values
返回地图中所有values
的数组 -
size
返回地图中的项目数 -
clear
清空地图
Instructions
Tests
tests:
- text: 存在地图数据结构。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; return (typeof test == "object")})(), "The Map data structure exists.");'
- text: Map对象具有以下方法:add,remove,get,has,values,clear和size。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; return (typeof test.add == "function" && typeof test.remove == "function" && typeof test.get == "function" && typeof test.has == "function" && typeof test.values == "function" && typeof test.clear == "function" && typeof test.size == "function")})(), "The Map object has the following methods: add, remove, get, has, values, clear, and size.");'
- text: add方法将项添加到地图中。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; test.add(5,6); test.add(2,3); test.add(2,5); return (test.size() == 2)})(), "The add method adds items to the map.");'
- text: has方法对于添加的项返回true,对于缺少的项返回false。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; test.add("test","value"); return (test.has("test") && !test.has("false"))})(), "The has method returns true for added items and false for absent items.");'
- text: get方法接受键作为输入并返回关联的值。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; test.add("abc","def"); return (test.get("abc") == "def")})(), "The get method accepts keys as input and returns the associated values.");'
- text: values方法将存储在映射中的所有值作为数组中的字符串返回。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; test.add("a","b"); test.add("c","d"); test.add("e","f"); var vals = test.values(); return (vals.indexOf("b") != -1 && vals.indexOf("d") != -1 && vals.indexOf("f") != -1)})(), "The values method returns all the values stored in the map as strings in an array.");'
- text: clear方法清空映射,size方法返回映射中存在的项目数。
testString: 'assert((function() { var test = false; if (typeof Map !== "undefined") { test = new Map() }; test.add("b","b"); test.add("c","d"); test.remove("asdfas"); var init = test.size(); test.clear(); return (init == 2 && test.size() == 0)})(), "The clear method empties the map and the size method returns the number of items present in the map.");'
Challenge Seed
var Map = function() {
this.collection = {};
// change code below this line
// change code above this line
};
Solution
// solution required