merge two sorted arrays, ignoring duplicates.

merge_unique.js

var merge_unique = function(array1, array2){
	var len1 = array1.length;
	var len2 = array2.length;
	var buff = []
	var i = 0, j = 0

	while(i != len1 && j != len2){
		if(array1[i] < array2[j])
			buff.push(array1[i++]);
		else
			buff.push(array2[j++]);

		while(array1[i] == buff[buff.length-1])
			i++;
		while(array2[j] == buff[buff.length-1])
			j++;
	}

	for(i; i < len1; i++){
		buff.push(array1[i]);
		while(array1[i] == buff[buff.length-1])
			i++;	
	}
	for(j; j < len2; j++){
		buff.push(array2[j]);
		while(array2[j] == buff[buff.length-1])
			j++;
	}
	
	return buff;
}

a1 = [1,2,3,4,5,6,7];

a2 = [3,4,5,6,7,8,9,10];

console.log(merge_unique(a1,a2));

console.log(merge_unique([],[]));

console.log(merge_unique([],[1]));

console.log(merge_unique([4],[1,1,1,1]));