blocks syntax.m

#import <Foundation/Foundation.h>

// typedef
typedef NSString*(^ConvertBlock)(NSString *text);

@interface Thing : NSObject
@property (nonatomic, strong) void (^coolPropertyBlock)(NSString *text); // Property

// method param
- (void)doSomething:(void(^)(NSString *text))block with:(NSString *)person;
@end

@implementation Thing

// method param
- (void)doSomething:(void(^)(NSString *text))block with:(NSString *)person {
	block(person);
}

@end

int main(int argc, char *argv[]) {
	@autoreleasepool {
		// Local variable
		CGFloat (^multiplyBlock)(CGFloat a, CGFloat b) = ^CGFloat(CGFloat a, CGFloat b) {
			return a * b;
		};
		NSLog(@"2 multiplyBlock 6 => %f", multiplyBlock(2, 6));
		
		Thing *t = [Thing new];
		// Property
		[t setCoolPropertyBlock:^void(NSString *text){ // as argument to a call
			NSLog(@"%@ is cool!", text);
		}];
		t.coolPropertyBlock(@"Alex");
		t.coolPropertyBlock(@"This");
		
		// as argument to a call
		[t doSomething:^void(NSString *person) {
			NSLog(@"I'm working with %@", person);
		} with:@"Robert"];
		
		// typedef
		ConvertBlock mayus = ^NSString*(NSString *text) {
			return [text uppercaseString];
		};
		ConvertBlock minus = ^NSString*(NSString *text) {
			return [text lowercaseString];
		};
		NSString *toConvert = @"Hello World!";
		NSLog(@"Convert '%@' to '%@'", toConvert, mayus(toConvert));
		NSLog(@"Convert '%@' to '%@'", toConvert, minus(toConvert));
	}
}