Javacript中自定义的map.js 的方法

 js中没有map这个类，只能自己写一个。以下map.js和map-util.js都是自定义的map，任选其一就可以。你可以用它来像java里new map()和put()、remove()、get()等方法。

map.js:

function map() {   
  var struct = function(key, value) {   
    this.key = key;   
    this.value = value;   
  }   
  var put = function(key, value){   
    for (var i = 0; i < this.arr.length; i++) {   
      if ( this.arr[i].key === key ) {   
        this.arr[i].value = value;   
        return;   
      }   
    }   
    this.arr[this.arr.length] = new struct(key, value);   
  }   
  var get = function(key) {   
    for (var i = 0; i < this.arr.length; i++) {   
      if ( this.arr[i].key === key ) {   
        return this.arr[i].value;   
      }   
    }   
    return null;   
  }   
  var remove = function(key) {   
    var v;   
    for (var i = 0; i < this.arr.length; i++) {   
      v = this.arr.pop();   
      if ( v.key === key ) {   
        continue;   
      }   
      this.arr.unshift(v);   
    }   
  }   
  var size = function() {   
    return this.arr.length;   
  }   
  var isempty = function() {   
    return this.arr.length <= 0;   
  }   
  this.arr = new array();   
  this.get = get;   
  this.put = put;   
  this.remove = remove;   
  this.size = size;   
  this.isempty = isempty;   
}   

map-util.js:

function map() { 
  this.elements = new array(); 
  var i; 
  //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) { 
    this.elements.push( { 
      key : _key, 
      value : _value 
    }); 
  }; 
  this.putfirst = function(_key, _value){ 
    var templist = this.elements; 
    this.elements = new array(); 
    this.elements.push( { 
      key : _key, 
      value : _value 
    }); 
    for(var i=0;i<templist.length;i++){ 
      this.elements.push( 
        templist[i] 
      ); 
    } 
  } 
  //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; 
  }; 
  //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; 
    } 
  }; 
  //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; 
  }; 
  //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; 
  }; 
} 

总结

以上所述是小编给大家介绍的 javacript中自定义的map.js  的方法，希望对大家有所帮助