block

基本使用：

int(^myBlock)(int, int) = ^(int a, int b){            return a + b;        };                        int sum = myBlock(10, 20);        NSLog(@"%d", sum);

 

提高：使多个block的声明不再冗长

typedef int (^MyBlock)(int, int);MyBlock sumBlock = ^(int a, int b){            return a + b;        };                MyBlock minusBlock = ^(int a, int b){            return a - b;        };                int sum = sumBlock(10, 20);        int minus = minusBlock(20, 10);                NSLog(@"%d, %d", sum, minus);