The difference between block and C language function pointers __ function

Block is an anonymous function with an automatic variable value.

1. The function pointer is a reference to the address of a function that has been determined at compile time. Block is a function object, which is produced during the process of program running. The block object generated in one scope is allocated on the stack (stack) and, like all other objects allocated on the stack, is absent from the scope.
2, blocks is inline, and it is read-only to local variables. If you want to modify the keyword: __block (note that two underscores).

3, as a function of the parameters, blocks a sense of substitution of the callback function or delegate. When the function is called, suppose an event triggers, then the contents of the blocks will run. This facilitates the integration and reading of the code, and you don't need to implement the delegate method everywhere.