the solution section was not getting shown on the screen for some unknown reasons.. anyways the below would be fine(without the edge cases handled)....:)

*****

function myFunction(arr){

var len = arr.length;

for(var i = 0; i < len; i++){

var ele = arr[i],

nxt = i < len ? arr[i+1] : arr[i],

msn = 0;

if(nxt - ele > 1){

msn = ele + 1;

return [msn];

}

}

return [msn];

}

*******