Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click If txtBack.Visible = True Or btnDisplay.Enabled = False Then 'if back of the flashcard is visible and if the start button has been clicked
我想要创建一个函数,我们称之为altHead,它接受2个变量并输出一个变量,这样:我想这样称呼它:它应该做的是查看第一个变量和列表如果列表为空,则返回第一个var的值;否则,返回该列表。altHead (x:xs) = if null[xs] then [x] else [xs]
但是,我相信x:xs只会查看列表。