@ 매크로

1.

    NSString *string = @"<#string#>"

2.  

    id express = @(<#expression#>)

  (ex)

    NSInteger idx = 40;

    NSString *idxString = [@(idx) stringValue];

3.    

    NSArray *array =  @[<#objects, ...#>]

4.    

    @autoreleasepool {

        <#statements#>

    }

5.    

    char[] chars =  @encode(<#type-name#>)

6.    

    Protocol *protocol = @protocol(<#protocol-name#>)

7.    

    SEL sel = @selector(<#selector#>)

8.    

    @throw <#expression#>

    

9.

    NSDictonary *dic = @{<#key#>: <#object, ...#>}

    

10.

    @try {

        <#Code that can potentially throw an exception#>

    }

    @catch (NSException *exception) {

        <#Handle an exception thrown in the @try block#>

    }

    @finally {

        <#Code that gets executed whether or not an exception is thrown#>

    }

11. structure

    CGSize theSize = {
        .width = 100.f,
        .height = 100.f,
    };

    

    CGRect theRect = {
        {.x = 10.f, .y= 10.f},
        {.width = 200.f, .height = 200.f}
    };