xcode - Whats the meaning of the "build&run" button's arrow?

Question

Out of curiosity, when you open xCode and you want to run your app, you must to click "Play" button:

But when you hover this section, a little arrow appears (downright)

Does anybody know the meaning of that element, I thought it was a hidden menu.

Answer 1

当您单击并按住该按钮时，将出现一个菜单，您可以在其中切换该按钮的默认操作。

您可以在此处查看其他选项：

请注意，您可以通过按住 shift（仅构建）、alt（首先为该方案调出方案选择器）或 ctrl（不构建，仅运行）来修改这些选项。