在Objective-C編程語言，為了保存的基本數(shù)據(jù)類型，如整型，浮點型，布爾對象的形式，
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. | 方法和說明 |
|---|---|
| 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. |
下面是一個簡單的例子，使用的NSNumber兩個數(shù)字相乘，并返回該產(chǎn)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; }
現(xiàn)在，當(dāng)我們編譯并運行程序，我們會得到以下的結(jié)果。
2013-09-14 18:53:40.575 demo[16787] The product is 105
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