What is the difference between readonly and readwrite in Objective C?

Question

任何人都可以告诉我iPhone SDK中的readonly和readwrite属性之间的区别吗？

Answer 1

readwrite Indicates that the property should be treated as read/write. This attribute is the default. Both a getter and setter method are required in the @implementation block. If you use the @synthesize directive in the implementation block, the getter and setter methods are synthesized.

readonly Indicates that the property is read-only. If you specify readonly, only a getter method is required in the @implementation block. If you use the @synthesize directive in the @implementation block, only the getter method is synthesized. Moreover, if you attempt to assign a value using the dot syntax, you get a compiler error.

For more visit this reference

Hope, this will help you..