JavaScript是一种强大的脚本语言，可以方便快捷地实现获取汉字首字母拼音、全拼音和混拼音的功能。实现此功能，可以使用JavaScript中的String对象的replace方法，如下所示：
// 定义拼音库
var pinyin_dict_firstletter = {
"a": "\u554a\u963f\u9515",
"ai": "\u57c3\u6328\u54ce\u5509\u54c0\u7691\u764c\u853c\u77ee\u827e\u788d\u7231\u9698\u8bf6\u6371\u55f3\u55cc\u5ad2\u7477",
"an": "\u978d\u6c28\u5b89\u4ffa\u6309\u6697\u5cb8\u80fa\u6848\u8c19\u57ef\u63de\u72b4\u5eb5\u6849\u94f5\u9e4c\u9878\u9eef",
"ang": "\u80ae\u6602\u76ce",
"ao": "\u51f9\u6556\u71ac\u7ff1\u8884\u50b2\u5965\u61ca\u6fb3\u5773\u62d7\u55f7\u5662\u5c99\u5ed2\u9068\u5aaa\u9a9c\u8071\u87af\u93ca\u9ccc\u93d6",
"ba": "\u82ad\u634c\u6252\u53ed\u5427\u7b06\u516b\u75a4\u5df4\u62d4\u8dcb\u9776\u628a\u8019\u575d\u9738\u7f62\u7238\u8307\u83dd\u8406\u636d\u5c9c\u705e\u6777\u94af\u7c91\u9c85\u9b43",
"bai": "\u767d\u67cf\u767e\u6446\u4f70\u8d25\u62dc\u7a17\u859c\u63b0\u97b4",
"ban": "\u6591\u73ed\u642c\u6273\u822c\u9881\u677f\u7248\u626e\u62cc\u4f34\u74e3\u534a\u529e\u7eca\u962a\u5742\u8c73\u94a3\u7622\u764d\u8228",
"bang": "\u90a6\u5e2e\u6886\u699c\u8180\u7ed1\u68d2\u78c5\u868c\u9551\u508d\u8c24\u84a1\u8783",
"bao": "\u82de\u80de\u5305\u8912\u96f9\u4fdd\u5821\u9971\u5b9d\u62b1\u62a5\u66b4\u8c79\u9c8d\u7206\u52f9\u8446\u5b80\u5b62\u7172\u9e28\u8913\u8db5\u9f85",
"bo": "\u5265\u8584\u73bb\u83e0\u64ad\u62e8\u94b5\u6ce2\u535a\u52c3\u640f\u94c2\u7b94\u4f2f\u5e1b\u8236\u8116\u818a\u6e24\u6cca\u9a73\u4eb3\u8543\u5575\u997d\u6a97\u64d8\u7934\u94b9\u9e41\u7c38\u8ddb",
"bei": "\u676f\u7891\u60b2\u5351\u5317\u8f88\u80cc\u8d1d\u94a1\u500d\u72c8\u5907\u60eb\u7119\u88ab\u5b5b\u9642\u90b6\u57e4\u84d3\u5457\u602b\u6096\u789a\u9e4e\u8919\u943e",
"ben": "\u5954\u82ef\u672c\u7b28\u755a\u574c\u951b",
"beng": "\u5d29\u7ef7\u752d\u6cf5\u8e66\u8ff8\u552a\u5623\u750f",
"bi": "\u903c\u9f3b\u6bd4\u9119\u7b14\u5f7c\u78a7\u84d6\u853d\u6bd5\u6bd9\u6bd6\u5e01\u5e87\u75f9\u95ed\u655d\u5f0a\u5fc5\u8f9f\u58c1\u81c2\u907f\u965b\u5315\u4ef3\u4ffe\u8298\u835c\u8378\u5421\u54d4\u72f4\u5eb3\u610e\u6ed7\u6fde\u5f3c\u59a3\u5a62\u5b16\u74a7\u8d32\u7540\u94cb\u79d5\u88e8\u7b5a\u7b85\u7be6\u822d\u895e\u8df8\u9ac0",
"bian": "\u97ad\u8fb9\u7f16\u8d2c\u6241\u4fbf\u53d8\u535e\u8fa8\u8fa9\u8fab\u904d\u533e\u5f01\u82c4\u5fed\u6c74\u7f0f\u7178\u782d\u78a5\u7a39\u7a86\u8759\u7b3e\u9cca",
"biao": "\u6807\u5f6a\u8198\u8868\u5a4a\u9aa0\u98d1\u98d9\u98da\u706c\u9556\u9573\u762d\u88f1\u9cd4",
"bie": "\u9cd6\u618b\u522b\u762a\u8e69\u9cd8",
"bin": "\u5f6c\u658c\u6fd2\u6ee8\u5bbe\u6448\u50a7\u6d5c\u7f24\u73a2\u6ba1\u8191\u9554\u9acc\u9b13",
"bing": "\u5175\u51b0\u67c4\u4e19\u79c9\u997c\u70b3\u75c5\u5e76\u7980\u90b4\u6452\u7ee0\u678b\u69df\u71f9",
"bu": "\u6355\u535