发布于 2015-07-05 11:51:28 | 242 次阅读 | 评论: 0 | 来源: 网络整理
在Objective-C编程语言，为了保存的基本数据类型，如整型，浮点型，布尔对象的形式，
Objective-C中提供了一系列的NSNumber和重要的工作方法是下表中列出。
| S.N. | 方法和说明 |
|---|---|
| 1 | + (NSNumber *)numberWithBool:(BOOL)value Creates and returns an NSNumber object containing a given value, treating it as a BOOL. |
| 2 | + (NSNumber *)numberWithChar:(char)value Creates and returns an NSNumber object containing a given value, treating it as a signed char. |
| 3 | + (NSNumber *)numberWithDouble:(double)value Creates and returns an NSNumber object containing a given value, treating it as a double. |
| 4 | + (NSNumber *)numberWithFloat:(float)value Creates and returns an NSNumber object containing a given value, treating it as a float. |
| 5 | + (NSNumber *)numberWithInt:(int)value Creates and returns an NSNumber object containing a given value, treating it as a signed int. |
| 6 | + (NSNumber *)numberWithInteger:(NSInteger)value Creates and returns an NSNumber object containing a given value, treating it as an NSInteger. |
| 7 | - (BOOL)boolValue Returns the receiver's value as a BOOL. |
| 8 | - (char)charValue Returns the receiver's value as a char. |
| 9 | - (double)doubleValue Returns the receiver's value as a double. |
| 10 | - (float)floatValue Returns the receiver's value as a float. |
| 11 | - (NSInteger)integerValue Returns the receiver's value as an NSInteger. |
| 12 | - (int)intValue Returns the receiver's value as an int. |
| 13 | - (NSString *)stringValue Returns the receiver's value as a human-readable string. |
下面是一个简单的例子，使用的NSNumber两个数字相乘，并返回该产品。
#import <Foundation/Foundation.h>
@interface SampleClass:NSObject
- (NSNumber *)multiplyA:(NSNumber *)a withB:(NSNumber *)b;
@end
@implementation SampleClass
- (NSNumber *)multiplyA:(NSNumber *)a withB:(NSNumber *)b
{
float number1 = [a floatValue];
float number2 = [b floatValue];
float product = number1 * number2;
NSNumber *result = [NSNumber numberWithFloat:product];
return result;
}
@end
int main()
{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
SampleClass *sampleClass = [[SampleClass alloc]init];
NSNumber *a = [NSNumber numberWithFloat:10.5];
NSNumber *b = [NSNumber numberWithFloat:10.0];
NSNumber *result = [sampleClass multiplyA:a withB:b];
NSString *resultString = [result stringValue];
NSLog(@"The product is %@",resultString);
[pool drain];
return 0;
}
现在，当我们编译并运行程序，我们会得到以下的结果。
2013-09-14 18:53:40.575 demo[16787] The product is 105