best practice to iterate through array of arrays & create another array [Android] : i have an Array of Arrays such as

    Arraylist<myObjec> subArray = {item1_1,item1_2, item1_3}<br></br>
    Arraylist<myObjec> subArray = {item2_1,item2_2, item2_3, item2_4}

    Arraylist<myObjec> mainArray = {subArray_1,subArray_2}

i want to create the newArray to be something like that:

    newArray = {item1_1, item1_2, item2_1, item2_2, item1_3, item2_3, item2_4}

So i want to take a segment of item say get from every subArray 2 item and go back through array of Arrays till i finish.

what would be the best practices to approach this result?