JavaScript数组去重的两种方法推荐

var aa=[1,3,5,4,3,3,1,4]
function arr(arr) {
  var result=[]
  for(var i=0; i<arr.length; i++){
    if(result.indexOf(arr[i])==-1){
      result.push(arr[i])
    }
  }
  console.log(result)
}      
arr(aa)

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;
}