自定义map对象，用于再不支持es6的map的时候
function Map() {
this.elements = new Array();
// 获取Map元素个数
this.size = function() {
return this.elements.length;
},
// 判断Map是否为空
this.isEmpty = function() {
return (this.elements.length < 1);
},
// 删除Map所有元素
this.clear = function() {
this.elements = new Array();
},
// 向Map中增加元素（key, value)
this.put = function(_key, _value) {
if (this.containsKey(_key) == true) {
if (this.containsValue(_value)) {
if (this.remove(_key) == true) {
this.elements.push({
key: _key,
value: _value
});
}
} else {
this.elements.push({
key: _key,
value: _value
});
}
} else {
this.elements.push({
key: _key,
value: _value
});
}
},
// 向Map中增加元素（key, value)
this.set = function(_key, _value) {
if (this.containsKey(_key) == true) {
if (this.containsValue(_value)) {
if (this.remove(_key) == true) {
this.elements.push({
key: _key,
value: _value
});
}
} else {
this.elements.push({
key: _key,
value: _value
});
}
} else {
this.elements.push({
key: _key,
value: _value
});
}
},
// 删除指定key的元素，成功返回true，失败返回false
this.remove = function(_key) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
this.elements.splice(i, 1);
return true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 删除指定key的元素，成功返回true，失败返回false
this.delete = function(_key) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
this.elements.splice(i, 1);
return true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 获取指定key的元素值value，失败返回null
this.get = function(_key) {
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
return this.elements[i].value;
}
}
} catch (e) {
return null;
}
},
// set指定key的元素值value
this.setValue = function(_key, _value) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
this.elements[i].value = _value;
return true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 获取指定索引的元素（使用element.key，element.value获取key和value），失败返回null
this.element = function(_index) {
if (_index < 0 || _index >= this.elements.length) {
return null;
}
return this.elements[_index];
},
// 判断Map中是否含有指定key的元素
this.containsKey = function(_key) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
bln = true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 判断Map中是否含有指定key的元素
this.has = function(_key) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].key == _key) {
bln = true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 判断Map中是否含有指定value的元素
this.containsValue = function(_value) {
var bln = false;
try {
for (i = 0; i < this.elements.length; i++) {
if (this.elements[i].value == _value) {
bln = true;
}
}
} catch (e) {
bln = false;
}
return bln;
},
// 获取Map中所有key的数组（array）
this.keys = function() {
var arr = new Array();
for (i = 0; i < this.elements.length; i++) {
arr.push(this.elements[i].key);
}
return arr;
},
// 获取Map中所有value的数组（array）
this.values = function() {
var arr = new Array();
for (i = 0; i < this.elements.length; i++) {
arr.push(this.elements[i].value);
}
return arr;
};
/**
* map遍历数组
* @param callback [function] 回调函数；
* @param context [object] 上下文；
*/
this.forEach = function forEach(callback, context) {
context = context || window;
//IE6-8下自己编写回调函数执行的逻辑
var newAry = new Array();
for (var i = 0; i < this.elements.length; i++) {
if (typeof callback === 'function') {
var val = callback.call(context, this.elements[i].value, this.elements[i].key, this.elements);
newAry.push(this.elements[i].value);
}
}
return newAry;
}
}
