数组去重方法，万能用法

Array.prototype.arrUniq = function() {
  var temp, arrVal,
    array = this,
    arrClone = array.concat(), //克隆数组
    typeArr = { //数组原型
      'obj': '[object Object]',
      'fun': '[object Function]',
      'arr': '[object Array]',
      'num': '[object Number]'
    },
    ent = /(\u3000|\s|\t)*(\n)+(\u3000|\s|\t)*/gi; //空白字符正则

  //把数组中的object和function转换为字符串形式
  for (var i = arrClone.length; i--;) {
    arrVal = arrClone[i];
    temp = Object.prototype.toString.call(arrVal);

    if (temp == typeArr['num'] && arrVal.toString() == 'NaN') {
      arrClone[i] = arrVal.toString();
    }

    if (temp == typeArr['obj']) {
      arrClone[i] = JSON.stringify(arrVal);
    }

    if (temp == typeArr['fun']) {
      arrClone[i] = arrVal.toString().replace(ent, '');
    }
  }

  //去重关键步骤
  for (var i = arrClone.length; i--;) {
    arrVal = arrClone[i];
    temp = Object.prototype.toString.call(arrVal);

    if (temp == typeArr['arr']) arrVal.arrUniq(); //如果数组中有数组，则递归
    if (arrClone.indexOf(arrVal) != arrClone.lastIndexOf(arrVal)) { //如果有重复的，则去重
      array.splice(i, 1);
      arrClone.splice(i, 1);
    } else {
      if (Object.prototype.toString.call(array[i]) != temp) {
        //检查现在数组和原始数组的值类型是否相同，如果不同则用原数组中的替换，原因是原数组经过了字符串变换
        arrClone[i] = array[i];
      }
    }
  }
  return arrClone;
}

//用法
array.arrUniq();

用在angularJS，追踪某一项特定值

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

//用法
unique(array,'id');