JS去除数组重复值的五种不同方法

  Array.prototype.method1 = function(){ 
      var arr[];  //定义一个临时数组 
      for(var i = 0; i < this.length; i++){  //循环遍历当前数组 
        //判断当前数组下标为i的元素是否已经保存到临时数组 
        //如果已保存，则跳过，否则将此元素保存到临时数组中 
        if(arr1.indexOf(this[i]) == -1){ 
          arr.push(this[i]); 
        } 
      } 
      return arr; 
    }

Array.prototype.method2 = function(){ 
      var h{};  //定义一个hash表 
      var arr[]; //定义一个临时数组 
       
      for(var i = 0; i < this.length; i++){  //循环遍历当前数组 
        //对元素进行判断，看是否已经存在表中，如果存在则跳过，否则存入临时数组 
        if(!h[this[i]]){ 
          //存入hash表 
          h[this[i]] = true; 
          //把当前数组元素存入到临时数组中 
          arr.push(this[i]); 
        } 
      } 
      return arr; 
    } 

Array.prototype.method3 = function(){ 
      //直接定义结果数组 
      var arr[this[0]]; 
      for(var i = 1; i < this.length; i++){  //从数组第二项开始循环遍历此数组 
        //对元素进行判断： 
        //如果数组当前元素在此数组中第一次出现的位置不是i 
        //那么我们可以判断第i项元素是重复的，否则直接存入结果数组 
        if(this.indexOf(this[i]) == i){ 
          arr.push(this[i]); 
        } 
      } 
      return arr; 
     
    } 

Array.prototype.method4 = function(){ 
      //将数组进行排序 
      this.sort(); 
      //定义结果数组 
      var arr[this[0]]; 
      for(var i = 1; i < this.length; i++){  //从数组第二项开始循环遍历数组 
        //判断相邻两个元素是否相等，如果相等说明数据重复，否则将元素写入结果数组 
        if(this[i] !== arr[arr.length - 1]){ 
          arr.push(this[i]); 
        }       
      } 
      return arr; 
       
    } 

 var arr = [112,112,34,'你好',112,112,34,'你好','str','str1']; 
    alert(arr.method3()); 

function unique(arr) {
  var result = [], isRepeated;
  for (var i = 0, len = arr.length; i < len; i++) {
    isRepeated = false;
    for (var j = 0, len = result.length; j < len; j++) {
      if (arr[i] == result[j]) {  
        isRepeated = true;
        break;
      }
    }
    if (!isRepeated) {
      result.push(arr[i]);
    }
  }
  return result;
}

function unique(arr) {
  var result = [], hash = {};
  for (var i = 0, elem; (elem = arr[i]) != null; i++) {
    if (!hash[elem]) {
      result.push(elem);
      hash[elem] = true;
    }
  }
  return result;
}

<script>
var h_hewenqiArray = new Array();
h_hewenqiArray[0] = "jb51.net";
h_hewenqiArray[1] = "easysector";
h_hewenqiArray[2] = "jb51.net";
h_hewenqiArray[3] = "keleyi";
h_hewenqiArray[4] = "keleyi";
h_hewenqiArray[5] = "脚本之家";
h_hewenqiArray[6] = "jb51.net";
h_hewenqiArray[7] = "hoverclock";
h_hewenqiArray[8] = "yestop";
h_hewenqiArray[9] = 163;
h_hewenqiArray[10] = "脚本之家";
h_hewenqiArray[11] = 163;
h_hewenqiArray[12] = "hoverclock";
h_hewenqiArray[13] = "脚本之家";

var h_arrayLength = h_hewenqiArray.length;
document.write("原始数组元素个数："+h_arrayLength + "<br />");
for (var i = 0; i < h_arrayLength; i++)
{
document.write(h_hewenqiArray[i]+"<br />");
}


function hovercUnique(arr) {
var result = [], hash = {};
for (var i = 0, elem; (elem = arr[i]) != null; i++) {
if (!hash[elem]) {
result.push(elem);
hash[elem] = true;
}
}
return result;
//http://jb51.net.com
}

var h_hewenqiResult = hovercUnique(h_hewenqiArray);

var h_resultLength = h_hewenqiResult.length;
document.write("<br />去重复后数组元素个数：" + h_resultLength + "<br />");
for (var i = 0; i < h_resultLength; i++) {
document.write(h_hewenqiResult[i] + "<br />");
} 
</script>