If the empty bracket pair is omitted, it is an error, but an error that the compiler is unlikely to catch; the program may fail at run time.

如果遗漏了空方括号对，这是一个编译器无法发现的错误，将导致程序在运行时出错。

youdao

But you can also imagine a positive kerning pair when a 'f' is followed by a bracket for example; "f".

但你可以想象一个字距配对为正的例子：一个小写f后跟随一个括号，例如：“f”。

youdao

A bolt pair (4) and a hanger (1) are fixedly connected above the two axial sides of a bracket (2) mounting hole or a slot respectively.

所述托架(2)安装孔或槽径向两侧的上方分别有螺栓副(4)与吊架(1)固定连接。

youdao