Heim > Web-Frontend > js-Tutorial > JS 实现Json查询的方法实例_javascript技巧

JS 实现Json查询的方法实例_javascript技巧

WBOY
Freigeben: 2016-05-16 17:37:16
Original
1059 Leute haben es durchsucht

     其实很简单,我这部分代码,前一部分是简单的实现如何使用JS写模板,第二个就是具体的实现了JSON查询的一个扩展。

     以后查询Json就有了利器了。

复制代码 代码如下:

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

            var count = 0;

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

            for (var i = 1; i                 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);
                    fn = _cache[exp] = _complite(code);
                }
                return fn(this);
            } catch (e) {
                return [];
            }
        }

        var doTest = function () {

            var heros = [
            // 名============攻=====防=======力量====敏捷=====智力====
                {name: '冰室女巫', DP: 38, AP: 1.3, Str: 16, Dex: 16, Int: 21 },
                { name: '沉默术士', DP: 39, AP: 1.1, Str: 17, Dex: 16, Int: 21 },
                { name: '娜迦海妖', DP: 51, AP: 6.0, Str: 21, Dex: 21, Int: 18 },
                { name: '赏金猎人', DP: 39, AP: 4.0, Str: 17, Dex: 21, Int: 16 },
                { name: '剧毒术士', DP: 45, AP: 3.1, Str: 18, Dex: 22, Int: 15 },
                { name: '光之守卫', DP: 38, AP: 1.1, Str: 16, Dex: 15, Int: 22 },
                { name: '炼金术士', DP: 49, AP: 0.6, Str: 25, Dex: 11, Int: 25 }
            //...
            ];

            var match = heros.Query('@Str>20 AND @Dex>20');
            ShowResult(match[0]);

            // 查询:“士”结尾的
            // 结果:沉默术士,剧毒术士,炼金术士
            var match = heros.Query('right(@name,1)="士"');
            ShowResult(match[0]);
        }

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


     代码就是这样了。欢迎大家拍砖,或者可以提出新的想法。我们一起来扩展
Verwandte Etiketten:
Quelle:php.cn
Erklärung dieser Website
Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn
Beliebte Tutorials
Mehr>
Neueste Downloads
Mehr>
Web-Effekte
Quellcode der Website
Website-Materialien
Frontend-Vorlage