JS 實作Json查詢的方法實例_javascript技巧

     其實很簡單，我這部分程式碼，前一部分是簡單的實作如何使用JS寫模板，第二個就是具體的實作了JSON查詢的一個擴充。

     以後查詢Json就有了利器了。

複製程式碼 程式碼如下:

/*
         * 定义模板函数
        */
        var template = function (queryArr) {

            var count = 0;

            for (var i = 0; i < queryArr.length; i++) {

var e = queryArr[i];

if ($express) {
count++;
}
}

return count;
}

/*
* 模板创建函数
*/
var createIntance = function (exp) {
var fun = template.toString().replace("$express", exp).toString();
return eval("0," + fun);
}

var testTodo = function () {

var testArr = [
{ name: "张三", age: 20 },
{ name: "李四", age: 25 },
{ name: "王二麻子", age: 28 },
{ name: "小张", age: 30 }
];

var func = createIntance("e.age>=25");

            alert(func(testArr));
        }

        /****************** JS 实现 JSON查询 **********************/

        // 定义常用的函数
        var len = function (s) { return s.length; }
        var left = function (s, n) { return s.substr(0, n); }
        var right = function (s, n) { return s.substr(-n); }
        var index = function (s, find) { return s.indexOf(find) + 1; }

        // 扩展原型方法
        var _proto = Object.prototype;

        // 缓存,解决快速查找
        var _cache = {};

        // 扩展运算符
        var _alias = [
            /@/g, "_e.",
            /AND/gi, "&&",
            /OR/gi, "||",
            /<>/g, "!=",
            /NOT/gi, "!",
            /([^=<>])=([^=]|$)/g, '$1==$2'
        ];

        var _rQuote = /""/g;
        var _rQuoteTemp = /!~/g;

        // 编译
        var _complite = function (code) {
            return eval("0," + code);
        }

        // 将扩展符号转换成标准的JS符号
        var _interpret = function (exp) {
            exp = exp.replace(_rQuote,"!~");
            var arr = exp.split('"');
            var i, n = arr.length;
            var k = _alias.length;

            for (var i = 0; i < n; i += 2) {
var s = arr[i];
for (var j = 0; j < k; j += 2) {
if (index(s, _alias[j]) > -1) {
                        s = s.replace(_alias[j], _alias[j + 1]);
                    }
                }
                arr[i] = s;
            }

            for (var i = 1; i < n; i += 2) {
                arr[i] = arr[i].replace(_rQuoteTemp, '\\"');
            }
            return arr.join('"');
        }

        // 定义模函数
        var _templ = function (_list) {
            var _ret = [];
            var _i = -1;

            for (var _k in _list) {
                var _e = _list[_k];
                if (_e != _proto[_k]) {
                    if ($C) {
                        _ret[++_i] = _e;
                    }
                }
            }
            return _ret;
        } .toString();

        // 扩展查询的方法
        _proto.Query = function (exp) {
            if (!exp) {
                return [];
            }

            var fn = _cache[exp];

            try {
                 _interpret(exp);
                    code = _templ.replace("$C", [exp ] = _complite(code);
                }
           e) {
               已被 [];
           
        var doTest = function () {

            智力====
                {name: '冰室女巫', DP: 38, AP: 1.3, Str: 16, Dex: 16, Int: 21 },                { name: '加海妖', DP: 51, AP. : 18 },

                { name: '賞金獵人', DP: 39, AP: 4.0, Str: 17, Dex: 21, 39, AP: 4.0, Str: 17, Dex: 21, 39, AP: 4.0.  { name: '劇毒術士', DP 。 22 },

                { name: '煉金術士', DP: 49, AP: 0.6, Str: 25,            ];

            var match = heros.Query('@Str>20 AND @Dex>20');
            // 查詢：「士」結尾的
            // 結果：沉默術士,劇毒術士,煉金術士
              ShowResult(match[0]) ;
        }

        function ShowResult(result) {
            alert(result.name " " result.DP " " result.AP "」Str  }

     程式碼就是這樣了。歡迎大家拍磚，或是可以提出新的想法。我們一起來擴充