objective-c - 使用@[array, of, items] vs [NSArray arrayWithObjects :]

Question

有区别吗

NSArray *myArray = @[objectOne, objectTwo, objectThree];

和

NSArray *myArray = [NSArray arrayWithObjects:objectOne, objectTwo, objectThree, nil];

一个比另一个更受欢迎吗？

Answer 1

它们几乎相同，但不完全相同。 Objective-C Literals 上的 Clang 文档状态:

Array literal expressions expand to calls to +[NSArray arrayWithObjects:count:], which validates that all objects are non-nil. The variadic form, +[NSArray arrayWithObjects:] uses nil as an argument list terminator, which can lead to malformed array objects.

所以

NSArray *myArray = @[objectOne, objectTwo, objectThree];

如果 objectTwo == nil 会抛出运行时异常，但是

NSArray *myArray = [NSArray arrayWithObjects:objectOne, objectTwo, objectThree, nil];

在这种情况下会创建一个只有一个元素的数组。