示例

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        struct date
        {
            int month;
            int day;
            int year;
        };
        
        struct date1
        {
            int month;
            int day;
            int year;
        } todaysDate, purchaseDate; //定义结构的同时声明两个变量
        
        struct
        {
            int month;
            int day;
            int year;
        } todaysDate1 = { 9, 25, 2014 }; //定义结构的同时声明变量并赋初值
        
        struct
        {
            int month;
            int day;
            int year;
        } dates[100]; //定义结构的同时声明数组
        
        struct date today;
        
        today.month = 9;
        today.day = 25;
        today.year = 2004;
        
        // %.2i 强制显示两位数,例如 05
        NSLog(@"Today's date is %i/%i/%.2i.", today.month,
              today.day, today.year % 100);
        
        // 初始化结构
        struct date tomorrow = { 9, 26, 2004 };
        struct date tomorrow1 = { 9 };
        struct date tomorrow2 = { .month = 9, .day = 26, .year = 2004};
        struct date tomorrow3 = { .year = 2004 };
        
        /* 点 */
        struct CGPoint {
            CGFloat x;
            CGFloat y;
        };
        typedef struct CGPoint CGPoint;
        
        /* 宽和高的尺寸 */
        struct CGSize {
            CGFloat width;
            CGFloat height;
        };
        typedef struct CGSize CGSize;
        
        /* 矩形 */
        struct CGRect {
            CGPoint origin;
            CGSize size;
        };
        typedef struct CGRect CGRect;
        
        CGPoint startPt;
        startPt.x = 100;
        startPt.y = 200;
        
        CGSize rectSize;
        rectSize.width = 200;
        rectSize.height = 100;
        
        CGRect theFrame;
        theFrame.origin = startPt;
        theFrame.size = rectSize;
        
        theFrame.size.width = 175;
        
        theFrame.origin.x = 0.0;
        theFrame.origin.y = 0.0;
    }
    return 0;
}

运行测试