JavaScript中模拟实现Java的集合类Map的常用方

JavaScript中模拟实现Java的集合类Map的常用方法

<span style="font-size:14px;">(function (){

function MapCache() {

var len = 0, cache = {};

this.put = function (key, value){

if ( key === null && key === undefined ){
throw new Error( " null or undefined is not a illegality variable ! " );
}

if (cache[ key + " " ] == undefined) {
cache[ key + " "] = value;
len++;
return;
}

cache[ key + " " ] = value;
};

this.get = function (key) {

return cache[ key + " " ];

};

this.remove = function (key) {

var value;

if ( key !== null || key !== undefined ) {
value = cache[ key + " " ];
delete cache[ key + " " ];
len--;
return value;
}

return value;
};

this.clear =  function () {
cache = {};
len = 0;
};

this.keys = function () {
var keys = [], prop;

for ( prop in cache ){
keys.push( prop.substring(0, prop.length - 1) );
}

return keys;
};

this.size = function () {
return len;
};
}

// 遵循 AMD 模块化规范， 支持RequireJS 模块化导出
if ( typeof define === 'function' && define.amd ) {
define('jmap', [], function (){
return MapCache;
})
}

return MapCache;
}());</span>