var arr = [[1,2,2],[3,4,5,5],[6,7,8,9,[11,12,[12,13,[14]]]],10];
var flatten = function(arr){
    return arr.reduce(
        function(acc, val){
            return acc.concat(Array.isArray(val) ? flatten(val) : val)
        }, []
    );
};
var arr1 = flatten(arr);
console.log(arr1);
//[1, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12, 13, 14, 10]
for(var i = arr1.length-1;i>-1;i--){
  for(var j = arr1.length-1;j>-1;j--){
    if(arr1[j]<arr1[j-1]){
      var t = arr1[j];
      arr1[j] = arr1[j-1];
      arr1[j-1] = t;
    }
    if(arr1[j] == arr1[j-1]&&j!=arr1.length-1){
      arr1[j] = arr1[j+1];
      
    }
    if(arr1[arr1.length-1] == arr1[arr1.length-2]&&arr1.length>1){
      arr1.length--;
    }
   
  }
   
}

console.log(arr1);
//[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]

改进版

var arr = [[1,2,2],[3,4,5,5],[6,7,8,9,[11,12,[12,13,[14]]]],10];
var flatten = function(arr){
    return arr.reduce(
        function(acc, val){
            return acc.concat(Array.isArray(val) ? flatten(val) : val)
        }, []
    );
};
var arr1 = flatten(arr);
console.log(arr1);
//[1, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12, 13, 14, 10]
function sortNumber(a,b)
{
return a - b
}
var arry2 = arr1.sort(sortNumber)
console.log(arry2);
/*var set = new Set(arry2);
for (let i of set) {
  console.log(i)
}*/
function dedupe(array) {
  return Array.from(new Set(array));
}
var arr3 = dedupe(arry2);

console.log(arr3);

改进版更改了排序与去重的部分,运用JavaScript自带的函数与容器,完爆之前蹩脚的冒泡排序.

在线编译地址:https://jsbin.com/miyepowaga/edit?js,console,output

Notes:

Array.isArray(obj)//如果对象是 Array，则为true; 否则为false。

https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray