That is, it copies the character in the same column from the line immediately above the cursor. For example, a CTRL-Y in the following situation would insert an "m" at the cursor.

也就是说，它将从紧挨着游标的上一行中复制同一列中的字符。

youdao

Place the cursor on the array name — m, in this case — and click on the button showing a pair of glasses. If it is not present already, the speedbar should appear and display the array name and type.

将光标置于数组名上(本例中为m)，单击样子为一对眼镜的按钮，speedbar会出现并显示数组的名字和类型。

youdao

And now notice as promised, I'm using a Mac here so my cursor is not actually blinking, but the cursor is waiting there for me.

现在注意正如所承诺的，这里我用的是苹果电脑,所以我的光标不会闪烁，但是光标在那里等我输入。

哈佛公开课 - 计算机科学课程节选