void foo(int (^blkParam)()){    NSLog(@"foo param %d",blkParam());}void run(){    //定义 返回值类型 (^block的名称)(参数类型) = ^返回值类型(参数) {...};    void (^blk)(void) = ^{        NSLog(@"aaaaa");    };    //调用    blk();        //定义和调用一起    int aa = ^(NSString *var){        NSLog(@"sssss %@",var);        return 88;    }(@"trrrr");        NSLog(@"aaa = %d",aa);            int (^blk1)(void) = ^{        NSLog(@"bbbbb");        return 88888;    };    //作为参数,先定义    foo(blk1);    //作为参数,不先定义，直接写    foo(^{NSLog(@"ddddd");return 9999;});        }int main(int argc, const char * argv[]) {    @autoreleasepool {        // insert code here...        NSLog(@"Hello, World!");        //function_1(29,22.3);        run();    }    return 0;}