将数组添加到数组而不创建2D数组

我有一个数组word_array,我想在其中添加句子的所有单词.例如:

word_array = []
sentence_1 = "my first sentence"
sentence_2 = "my second sentence"

然后有:

word_array = ["my", "first", "sentence", "my", "second", "sentence"]

如果我使用split():

word_array << sentence_1.split
word_array << sentence_2.split 

我明白了:

word_array = [["my", "first", "sentence"], ["my", "second", "sentence"]]

我怎样才能避免在这里使用2D阵列？

使用concat.

word_array.concat(sentence_1.split)
word_array.concat(sentence_2.split)

它比使用更有效+,这使得一个新的数组.