boolean value

基本解釋

Also note that the methods do not return boolean values.
還要注意這些方法不返回布爾值。
Boolean values can take either of two truth values: Yes, True, and 1 are synonyms, as are No, False, and 0.
Boolean 值可取以下兩種真值：Yes、True 和 1 是同義詞，No、False 和 0 是同義詞。
The hasPrev() and hasNext() methods return Boolean values telling us whether there are elements preceding or following the current item, or whether we have reached the beginning or end of the stack.
hasPrev() 和 hasNext() 方法返回 Boolean 值，告訴我們當(dāng)前記錄之前或之后是否還有記錄，或者指示我們到達(dá)了堆棧頂部或堆棧尾部。

So even though we think of conditions as being Boolean values true or false, really underneath the hood true means anything other than zero.
即使我們考慮,布爾值的真假條件，在底層“真“表示非零。
哈佛公開課 - 計(jì)算機(jī)科學(xué)課程節(jié)選