JavaScript Group By Array

Question

Possible Duplicate:
array_count_values for javascript instead

Let\'s say I have simple JavaScript array like

Answer 1

You can loop through each index and save it in a dictionary and increment it when every that key is found.

count = {};
for(a in array){
  if(count[array[a]])count[array[a]]++;
  else count[array[a]]=1;
}

Output will be:

Boat: 1
Car: 2
Truck: 2