oc中的block使用心得

typedef   void (^ simpleBlock) (void);
typedef  double (^multiplyTwoValues)(double, double);
typedef   void (^ simpleTestBlock) (int ,int);
@implementation TJAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
     simpleBlock block =^{
        NSLog(@"this is a block");

    };

   block();
    multiplyTwoValues values=^(double x,double y)
    {

        return x *y;
    };
    NSLog(@"%.3f",values(2.0,3.0));
    simpleTestBlock  testBlock=^(int x,int y)
    {
        NSLog(@"--->%d",x+y);
    };
    testBlock(2,3);

    return YES;
}