JS method example to implement Json query_javascript skills

It’s actually very simple. In this part of my code, the first part is a simple implementation of how to use JS to write templates, and the second part is a specific implementation of an extension of JSON query.

There will be a powerful tool for querying Json in the future.

Copy code The code is as follows:

/*
         * 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 {
if (!fn) {
var code = _interpret(exp);
code = _templ.replace("$C ", code);
                                                                        ] = _complite (code); }
}

var doTest = function () {

var heos = [
// name ============ Attack ========== Power ======= Intelligence ==== <> {name: 'ice room witch', DP: 38, AP: 1.3, STR: 16, DEX: 16, int: 21},

{name: 'silent warlock', DP : 39, AP: 1.1, Str: 17, Dex: 16, Int: 21 },

                                                                                                                               : 18 },

{ name: 'Bounty Hunter', DP: 39, AP: 4.0, Str: 17, Dex: 21, Int: 16 },

: 45, AP: 3.1, Str: 18, Dex: 22, Int: 15 },
                                                                                                                                                         22 },
                                                                                                                                                                                                                                                             
var match = heroes.Query('@Str>20 AND @Dex>20');
ShowResult(match[0]);

// Query:                                                                                                                                                                                  ;
}

function ShowResult(result) {
} alert(result.name " " result.DP " " result.AP " " result.Str " " result.Dex " " result.Int);

}

This is the code. Everyone is welcome to make suggestions or come up with new ideas. Let’s expand together