案例
XSYPerson.h文件
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface XSYPerson : NSObject
- (void)setAge:(BOOL)age;
- (void)setWeight:(BOOL)weight;
- (void)setHeight:(BOOL)height;
- (BOOL)age;
- (BOOL)weight;
- (BOOL)height;
@end
NS_ASSUME_NONNULL_END
XSYPerson.m 文件
#import "XSYPerson.h"
#define AgeMask (1)
#define WeightMask (1 << 1)
#define HeightMask (1 << 2)
@implementation XSYPerson {
union {
char bits; // 用来存储共用体的数据
struct { // 解释作用
BOOL age : 1;
BOOL weight : 1;
BOOL height : 1;
};
} AgeWightHeight;
}
- (instancetype)init {
self = [super init];
if (self) {
}
return self;
}
- (void)setAge:(BOOL)age {
if (age) {
AgeWightHeight.bits |= age;
}else {
AgeWightHeight.bits &= ~AgeMask;
}
}
- (BOOL)age {
return !!(AgeWightHeight.bits & AgeMask);
}
- (void)setWeight:(BOOL)weight {
if (weight) {
AgeWightHeight.bits |= WeightMask;
}else {
AgeWightHeight.bits &= ~WeightMask;
}
}
- (BOOL)weight {
return !!(AgeWightHeight.bits & WeightMask);
}
- (void)setHeight:(BOOL)height {
if (height) {
AgeWightHeight.bits |= HeightMask;
}else {
AgeWightHeight.bits &= ~HeightMask;
}
}
- (BOOL)height {
return !!(AgeWightHeight.bits & HeightMask);
}
@end
使用
XSYPerson *person = [[XSYPerson alloc] init];
person.age = YES;
person.weight = NO;
person.height = YES;
NSLog(@"age %d, weight %d, heigt %d",person.age, person.weight, person.height);
打印：
age 1, weight 0, heigt 1
