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);