格式2

- (void)applicationDidEnterBackground:(UIApplication *)application {
    
    if (<#condition#>) {
        <#statements#>
    }
    
    for (<#type *object#> in <#collection#>) {
        <#statements#>
    }
    
    while (<#condition#>) {
        <#statements#>
    }
    
    do {
        <#statements#>
    } while (<#condition#>);
    
    switch (<#expression#>) {
        case <#constant#>:
            <#statements#>
            break;
            
        default:
            break;
    }
    
    typedef NS_ENUM(NSInteger, UIButtonType) {
        UIButtonTypeCustom = 0,
        UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0),
        
        UIButtonTypeDetailDisclosure,
        UIButtonTypeInfoLight,
        UIButtonTypeInfoDark,
        UIButtonTypeContactAdd,
        
        UIButtonTypeRoundedRect = UIButtonTypeSystem,
    };
    
    struct CLLocationCoordinate2D {
        CLLocationDegrees latitude;
        CLLocationDegrees longitude;
    };
}