{"id":160120,"date":"2024-05-08T13:23:51","date_gmt":"2024-05-08T05:23:51","guid":{"rendered":""},"modified":"2024-05-08T13:23:56","modified_gmt":"2024-05-08T05:23:56","slug":"%e5%89%8d%e7%ab%af-javascript-%e7%bc%96%e7%a8%8b%e5%ae%9e%e7%8e%b0%e5%93%88%e5%b8%8c%e8%a1%a8%e7%9a%84%e6%96%b9%e6%b3%95%e6%9c%89%e5%93%aa%e4%ba%9b","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/160120.html","title":{"rendered":"\u524d\u7aef JavaScript \u7f16\u7a0b\u5b9e\u73b0\u54c8\u5e0c\u8868\u7684\u65b9\u6cd5\u6709\u54ea\u4e9b"},"content":{"rendered":"

\"\u524d\u7aef<\/p>\n

JavaScript \u4e2d\u5b9e\u73b0\u54c8\u5e0c\u8868\u7684\u65b9\u6cd5\u4e3b\u8981\u6709\u5229\u7528\u5bf9\u8c61\uff08Object\uff09\u6216\u8005 Map \u7c7b\u578b<\/strong>\u3001\u4f7f\u7528\u6570\u7ec4\u5b58\u50a8\u952e\u503c\u5bf9\u5e76\u901a\u8fc7\u6563\u5217\u51fd\u6570\u6765\u5b9e\u73b0\u952e\u503c\u4e4b\u95f4\u7684\u6620\u5c04<\/strong>\u3002\u5728\u8fd9\u4e24\u79cd\u65b9\u5f0f\u4e2d\uff0c\u4f7f\u7528 Map \u7c7b\u578b\u662f\u6700\u63a8\u8350\u7684\u65b9\u6cd5\uff0c\u56e0\u4e3a\u5b83\u672c\u8eab\u5c31\u662f\u4e3a\u4e86\u5b58\u50a8\u952e\u503c\u5bf9\u800c\u8bbe\u8ba1\u7684\u6570\u636e\u7ed3\u6784\uff0c\u63d0\u4f9b\u4e86\u5982 .set()<\/code>\u3001.get()<\/code>\u3001.has()<\/code> \u7b49\u4fbf\u6377\u7684\u64cd\u4f5c\u65b9\u6cd5\uff0c\u5e76\u4e14\u62e5\u6709\u4e0e\u5bf9\u8c61\u4e0d\u540c\u7684\u5185\u5b58\u7ed3\u6784\uff0c\u4f7f\u5176\u5728\u5904\u7406\u5927\u91cf\u6570\u636e\u65f6\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u4f7f\u7528\u5bf9\u8c61\u5b9e\u73b0\u54c8\u5e0c\u8868<\/h3>\n<\/p>\n

\u5bf9\u8c61\u5728 JavaScript \u4e2d\u662f\u4e00\u79cd\u975e\u5e38\u57fa\u7840\u7684\u6570\u636e\u7ed3\u6784\uff0c\u53ef\u4ee5\u88ab\u7528\u6765\u6a21\u62df\u54c8\u5e0c\u8868\u3002\u5bf9\u8c61\u7684\u5c5e\u6027\u8bbf\u95ee\u673a\u5236\u672c\u8d28\u4e0a\u662f\u4e00\u79cd\u54c8\u5e0c\u6620\u5c04\uff0c\u8fd9\u4f7f\u5f97\u5728 JavaScript \u4e2d\u4f7f\u7528\u5bf9\u8c61\u4f5c\u4e3a\u54c8\u5e0c\u8868\u975e\u5e38\u65b9\u4fbf\u3002<\/p>\n<\/p>\n

\u521b\u5efa\u54c8\u5e0c\u8868<\/h4>\n<\/p>\n

let hashTable = {};<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u6dfb\u52a0\u5143\u7d20<\/h4>\n<\/p>\n
hashTable["key1"] = "value1";<\/p>\n
hashTable["key2"] = "value2";<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8bbf\u95ee\u5143\u7d20<\/h4>\n<\/p>\n
let value1 = hashTable["key1"];<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u68c0\u67e5\u952e\u662f\u5426\u5b58\u5728<\/h4>\n<\/p>\n
let hasKey1 = "key1" in hashTable;<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5220\u9664\u5143\u7d20<\/h4>\n<\/p>\n
delete hashTable["key1"];<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5c3d\u7ba1\u4f7f\u7528\u5bf9\u8c61\u662f\u5b9e\u73b0\u54c8\u5e0c\u8868\u7684\u4e00\u79cd\u7b80\u6613\u65b9\u6cd5\uff0c\u4f46\u5b83\u6709\u4e00\u4e2a\u9650\u5236\uff0c\u90a3\u5c31\u662f\u952e\u5fc5\u987b\u662f\u5b57\u7b26\u4e32\u6216\u8005\u7b26\u53f7\u7c7b\u578b\u3002<\/p>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528 Map \u7c7b\u578b\u5b9e\u73b0\u54c8\u5e0c\u8868<\/h3>\n<\/p>\n
Map \u662f ES6 \u4e2d\u65b0\u589e\u7684\u4e00\u4e2a\u96c6\u5408\u7c7b\u578b\uff0c\u65e8\u5728\u63d0\u4f9b\u66f4\u4f18\u8d8a\u7684\u952e\u503c\u5bf9\u5b58\u50a8\u673a\u5236\u3002<\/p>\n<\/p>\n
\u521b\u5efa\u54c8\u5e0c\u8868<\/h4>\n<\/p>\n
let hashMap = new Map();<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u6dfb\u52a0\u5143\u7d20<\/h4>\n<\/p>\n
hashMap.set("key1", "value1");<\/p>\n
hashMap.set("key2", "value2");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8bbf\u95ee\u5143\u7d20<\/h4>\n<\/p>\n
let value1 = hashMap.get("key1");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u68c0\u67e5\u952e\u662f\u5426\u5b58\u5728<\/h4>\n<\/p>\n
let hasKey1 = hashMap.has("key1");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5220\u9664\u5143\u7d20<\/h4>\n<\/p>\n
hashMap.delete("key1");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u83b7\u53d6\u6240\u6709\u952e<\/h4>\n<\/p>\n
for (let key of hashMap.keys()) {<\/p>\n
    console.log(key);<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u83b7\u53d6\u6240\u6709\u503c<\/h4>\n<\/p>\n
for (let value of hashMap.values()) {<\/p>\n
    console.log(value);<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
Map \u7c7b\u578b\u5728\u6027\u80fd\u65b9\u9762\u76f8\u8f83\u4e8e\u4f7f\u7528\u5bf9\u8c61\u4f5c\u4e3a\u54c8\u5e0c\u8868\u6709\u663e\u8457\u7684\u4f18\u52bf\uff0c\u7279\u522b\u662f\u5f53\u5b58\u50a8\u5927\u91cf\u6570\u636e\u65f6\uff0cMap \u63d0\u4f9b\u4e86\u66f4\u5feb\u7684\u67e5\u627e\u901f\u5ea6\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u81ea\u5b9e\u73b0\u6563\u5217\u51fd\u6570<\/h3>\n<\/p>\n
\u9664\u4e86\u4f7f\u7528\u5185\u7f6e\u7684\u5bf9\u8c61\u548cMap\u7c7b\u4e4b\u5916\uff0c\u6211\u4eec\u8fd8\u53ef\u4ee5\u901a\u8fc7\u5b9e\u73b0\u81ea\u5df1\u7684\u6563\u5217\u51fd\u6570\u6765\u521b\u5efa\u54c8\u5e0c\u8868\u3002<\/p>\n<\/p>\n
\u5b9a\u4e49\u6563\u5217\u51fd\u6570<\/h4>\n<\/p>\n
\u4e00\u4e2a\u57fa\u672c\u7684\u6563\u5217\u51fd\u6570\u901a\u5e38\u5c06\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u54c8\u5e0c\u7801\u3001\u8fd9\u4e2a\u54c8\u5e0c\u7801\u4e0e\u6570\u7ec4\u7684\u957f\u5ea6\u6709\u5173\u8054\uff0c\u786e\u4fdd\u6700\u7ec8\u7684\u7d22\u5f15\u503c\u80fd\u591f\u9002\u7528\u4e8e\u6570\u7ec4\u7684\u957f\u5ea6\u8303\u56f4\u5185\u3002<\/p>\n<\/p>\n
function hashStringToInt(string, tableSize) {<\/p>\n
    let hash = 17;<\/p>\n
    for (let i = 0; i < string.length; i++) {<\/p>\n
        hash = (13 * hash * string.charCodeAt(i)) % tableSize;<\/p>\n
    }<\/p>\n
    return hash;<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u521b\u5efa\u54c8\u5e0c\u8868\u7c7b<\/h4>\n<\/p>\n
class HashTable {<\/p>\n
  table = new Array(2001);<\/p>\n
  setItem = (key, value) => {<\/p>\n
    const idx = hashStringToInt(key, this.table.length);<\/p>\n
    this.table[idx] = value;<\/p>\n
  };<\/p>\n
  getItem = (key) => {<\/p>\n
    const idx = hashStringToInt(key, this.table.length);<\/p>\n
    return this.table[idx];<\/p>\n
  };<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u6dfb\u52a0\u5143\u7d20<\/h4>\n<\/p>\n
let myHashTable = new HashTable();<\/p>\n
myHashTable.setItem("firstName", "John");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8bbf\u95ee\u5143\u7d20<\/h4>\n<\/p>\n
let firstName = myHashTable.getItem("firstName");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u81ea\u5b9e\u73b0\u7684\u54c8\u5e0c\u8868\u7c7b\u53ef\u4ee5\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u66f4\u591a\u7684\u63a7\u5236\u548c\u4f18\u5316\u7a7a\u95f4\uff0c\u4f46\u662f\u9700\u8981\u81ea\u5df1\u5904\u7406\u4e00\u4e9b\u95ee\u9898\uff0c\u5982\u51b2\u7a81\u5904\u7406\u548c\u52a8\u6001\u6269\u5bb9\u3002<\/p>\n<\/p>\n
\u56db\u3001\u54c8\u5e0c\u8868\u7684\u51b2\u7a81\u89e3\u51b3<\/h3>\n<\/p>\n
\u5728\u5b9e\u73b0\u54c8\u5e0c\u8868\u65f6\uff0c\u51b2\u7a81\u662f\u907f\u514d\u4e0d\u4e86\u7684\u95ee\u9898\u3002\u4e24\u4e2a\u4e0d\u540c\u7684\u952e\u53ef\u80fd\u4f1a\u4ea7\u751f\u76f8\u540c\u7684\u54c8\u5e0c\u503c\u3002\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u6709\u591a\u79cd\u7b56\u7565\uff0c\u5176\u4e2d\u5305\u62ec\u94fe\u5730\u5740\u6cd5\u548c\u5f00\u653e\u5730\u5740\u6cd5\u3002<\/p>\n<\/p>\n
\u4f7f\u7528\u94fe\u5730\u5740\u6cd5<\/h4>\n<\/p>\n
\u5728\u94fe\u5730\u5740\u6cd5\u4e2d\uff0c\u6bcf\u4e00\u4e2a\u6570\u7ec4\u7684\u4f4d\u7f6e\u4e0d\u518d\u76f4\u63a5\u5b58\u50a8\u503c\uff0c\u800c\u662f\u5b58\u50a8\u4e00\u4e2a\u94fe\u8868\u3002\u5f53\u51b2\u7a81\u53d1\u751f\u65f6\uff0c\u51b2\u7a81\u7684\u5143\u7d20\u5c06\u88ab\u6dfb\u52a0\u5230\u94fe\u8868\u4e2d\u3002<\/p>\n<\/p>\n
class HashTable {<\/p>\n
    table = new Array(2001);<\/p>\n
    setItem = (key, value) => {<\/p>\n
        const idx = hashStringToInt(key, this.table.length);<\/p>\n
        if (this.table[idx]) {<\/p>\n
            this.table[idx].push([key, value]);<\/p>\n
        } else {<\/p>\n
            this.table[idx] = [[key, value]];<\/p>\n
        }<\/p>\n
    };<\/p>\n
    getItem = (key) => {<\/p>\n
        const idx = hashStringToInt(key, this.table.length);<\/p>\n
        if (!this.table[idx]) {<\/p>\n
            return null;<\/p>\n
        }<\/p>\n
        return this.table[idx].find(x => x[0] === key)[1];<\/p>\n
    };<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f7f\u7528\u5f00\u653e\u5730\u5740\u6cd5<\/h4>\n<\/p>\n
\u5f00\u653e\u5730\u5740\u6cd5\u5219\u662f\u5728\u6570\u7ec4\u4e2d\u5bfb\u627e\u4e0b\u4e00\u4e2a\u7a7a\u7684\u69fd\u4f4d\u6765\u89e3\u51b3\u51b2\u7a81\u3002\u5f53\u8ba1\u7b97\u51fa\u7684\u7d22\u5f15\u5df2\u7ecf\u88ab\u5360\u7528\u65f6\uff0c\u7b97\u6cd5\u5c06\u7ee7\u7eed\u68c0\u67e5\u4e0b\u4e00\u4e2a\u7d22\u5f15\uff0c\u76f4\u5230\u627e\u5230\u7a7a\u4f4d\u3002<\/p>\n<\/p>\n
\/\/ \u7565\u8fc7\u5177\u4f53\u4ee3\u7801\u5b9e\u73b0\uff0c\u6982\u5ff5\u6027\u63cf\u8ff0<\/p>\n
\u5728\u5f00\u59cb\u63a2\u7d22\u65f6\uff0c\u4f60\u9700\u8981\u8bbe\u5b9a\u4e00\u4e2a\u6b65\u957f\uff0c\u8fd9\u51b3\u5b9a\u4e86\u4f60\u5728\u6570\u7ec4\u4e2d\u79fb\u52a8\u7684\u95f4\u9694\u3002\u5982\u679c\u7b2c\u4e00\u4e2a\u8ba1\u7b97\u7684\u7d22\u5f15\u88ab\u5360\u7528\u4e86\uff0c\u5c31\u7528\u6b65\u957f\u51b3\u5b9a\u4e0b\u4e00\u4e2a\u7d22\u5f15\uff0c\u5e76\u68c0\u67e5\u8be5\u4f4d\u7f6e\u3002\u5982\u6b64\u91cd\u590d\uff0c\u76f4\u5230\u627e\u5230\u4e00\u4e2a\u7a7a\u4f4d\u7f6e\u4e3a\u6b62\u3002<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u7efc\u4e0a\uff0cJavaScript \u4e2d\u6709\u591a\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5b9e\u73b0\u54c8\u5e0c\u8868\uff0c\u6bcf\u79cd\u65b9\u6cd5\u5404\u6709\u4f18\u7f3a\u70b9\uff0c\u9002\u7528\u4e8e\u4e0d\u540c\u7684\u573a\u666f\u3002\u5f00\u53d1\u4eba\u5458\u53ef\u4ee5\u6839\u636e\u9700\u6c42\u9009\u62e9\u4f7f\u7528\u5bf9\u8c61\u3001Map\u6216\u662f\u81ea\u5b9a\u4e49\u5b9e\u73b0\uff0c\u5e76\u91c7\u7528\u5408\u9002\u7684\u51b2\u7a81\u89e3\u51b3\u7b56\u7565\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
1. \u524d\u7aef JavaScript \u7f16\u7a0b\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u5bf9\u8c61\u5b9e\u73b0\u54c8\u5e0c\u8868\u3002<\/strong> <\/p>\n
\u4f7f\u7528\u5bf9\u8c61\u5b9e\u73b0\u54c8\u5e0c\u8868\u53ef\u4ee5\u5c06\u952e\u503c\u5bf9\u5b58\u50a8\u5728\u5bf9\u8c61\u7684\u5c5e\u6027\u4e2d\uff0c\u5176\u4e2d\u6bcf\u4e2a\u5c5e\u6027\u7684\u540d\u79f0\u4f5c\u4e3a\u54c8\u5e0c\u8868\u4e2d\u7684\u952e\uff0c\u5bf9\u5e94\u7684\u503c\u4f5c\u4e3a\u54c8\u5e0c\u8868\u4e2d\u7684\u503c\u3002\u53ef\u4ee5\u4f7f\u7528\u5bf9\u8c61\u7684\u5c5e\u6027\u8d4b\u503c\u548c\u8bbf\u95ee\u64cd\u4f5c\u6765\u5b9e\u73b0\u63d2\u5165\u3001\u5220\u9664\u548c\u83b7\u53d6\u64cd\u4f5c\u3002<\/p>\n
2. \u524d\u7aef JavaScript \u7f16\u7a0b\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u6570\u7ec4\u5b9e\u73b0\u54c8\u5e0c\u8868\u3002<\/strong> <\/p>\n
\u4f7f\u7528\u6570\u7ec4\u5b9e\u73b0\u54c8\u5e0c\u8868\u53ef\u4ee5\u901a\u8fc7\u5c06\u952e\u54c8\u5e0c\u5316\u4e3a\u6570\u7ec4\u7d22\u5f15\u6765\u8fdb\u884c\u5b58\u50a8\uff0c\u5176\u4e2d\u6bcf\u4e2a\u7d22\u5f15\u5bf9\u5e94\u4e00\u4e2a\u6876(bucket)\uff0c\u6bcf\u4e2a\u6876\u4e2d\u53ef\u4ee5\u5b58\u50a8\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u53ef\u4ee5\u4f7f\u7528\u6570\u7ec4\u7684\u7d22\u5f15\u64cd\u4f5c\u6765\u5b9e\u73b0\u63d2\u5165\u3001\u5220\u9664\u548c\u83b7\u53d6\u64cd\u4f5c\u3002<\/p>\n
3. \u524d\u7aef JavaScript \u7f16\u7a0b\u4e2d\uff0c\u53ef\u4ee5\u501f\u52a9\u7b2c\u4e09\u65b9\u5e93\u5b9e\u73b0\u54c8\u5e0c\u8868\u3002<\/strong> <\/p>\n
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