How to make 2d array into one long array

Question

Simple question: how would I manipulate this array into one long array?

var array = Array( 
                Array(1,2,3),
                Array(2, 3, 4)
                Array(5, 3, 9)

                );
console.log(array)

var newArray =

Answer 1

simple answer:

var array = Array( 
            Array(1,2,3),
            Array(2, 3, 4),
            Array(3,4,5)
            );

var newArray = array[0].concat(array[1], array[2])
console.log(newArray)