Reduce Method

The array reduce() method in JavaScript is used to reduce the array to a single value and executes a provided function for each value of the array (from left-to-right) and the return value of the function is stored in an accumulator.

    var  pokemon = ["Squirtle", "Charmander", "Bulbasaur"];

    var  pokeLength  = pokemon.reduce(function(accumulator, current) {
        return  accumulator  +  current.length;
    }, 0);

Output

27