Merge two arrays keeping only unique values (v8)

function arrayUnique(array) {
  var a = array.concat();
  for (var i = 0; i < a.length; ++i) {
    for (var j = i + 1; j < a.length; ++j) {
      if (a[i] === a[j])
        a.splice(j--, 1);
    }
  }

  return a;
};

arrayUnique(arr1.concat(arr2));

// merge


// [2,3,4,5,6,8,9,11]

var merge = function(arr1, arr2) {
  var result = [], next;

  while (arr1.length && arr2.length) {

    // if (arr1[0] <= arr2[0]) {
    //   result.push(arr1.shift());
    // } else {
    //   result.push(arr2.shift());
    // }
    result.push(( arr1[0] <= arr2[0] ) ? arr1.shift() : arr2.shift());

  }
  return result.concat(arr1).concat(arr2);
}

 

var merge = function(arr1, arr2) {
  var result = [], next;

  while (arr1.length && arr2.length) {
    result.push(( arr1[0] <= arr2[0] ) ? arr1.shift() : arr2.shift());
  }
  return result.concat(arr1).concat(arr2);
 

var merge = function(arr1, arr2) {
  var result = [], indexOne =0, indexTwo = 0;

  while (indexOne < arr1.length && indexTwo < arr2.length) {
   if (arr1[indexOne] <= arr2[indexTwo] ) {
     result.push(arr1[indexOne]);
     indexOne++
    } else {
     result.push(arr2[indexTwo]);
     indexTwo++
    }
  }
  return result.concat(arr1.slice(indexOne)).concat(arr2.slice(indexTwo));
}

var merge = function (one, two) {
    var combined = [];
    while (one.length > 0 && two.length > 0) {
        var smaller = one[0] < two[0] ? one : two;
        combined.push(smaller.shift());
    }
    return combined.concat(one, two);
};

merge(arr1,arr2)