OC对C类型的包装NSNumber
由于NSNumber是个Object通过指针调用,而C类型是基本类型,是直接调用内存.
- (NSNumber *)initWithChar:(char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedChar:(unsigned char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithShort:(short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedShort:(unsigned short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInt:(int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInt:(unsigned int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLong:(long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLong:(unsigned long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLongLong:(long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLongLong:(unsigned long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithFloat:(float)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithDouble:(double)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithBool:(BOOL)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER;
快速转换
除了写NSNumber的初始化类之外,还可以通过基本类型前加”@”快速转换.
int a = 1;
NSLog(@"%d",a);
NSLog(@"%@",@2);
id str = @3;
NSLog(@"%@",str);
NSNumber *num = [[NSNumber alloc]initWithInt:@"4"];
NSLog(@"%@",num);
例如,示例代码中str本身就是个NSNumber的类,由”@3”快速转换而成.
