js 数组去重

方法一：

        var arr = [1, 1, 1, 3, 2, 3, 3, 4];
        console.info(unique(arr));

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

方法二：

        function unique(arr) {
            var newArr = [];
            for (var i = 0; i < arr.length; i++) {
                if (arr.indexOf(arr[i]) == i) {
                    newArr.push(arr[i]);
                }
            }

            return newArr;
        }

方法三：

        var arr = [1, 1, 1, 3, 2, 3, 3, 4];
        console.info(unique(arr));

        function unique(arr) {
            var newArr = [];
     
            for (var i = 0, len = arr.length; i < len; i++) {
                if (newArr.indexOf(arr[i]) == -1) {
                    newArr.push(arr[i]);
                }
            }
            return newArr;
        }