数字对象NSNumber总结

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1.创建和初始化类方法
  形式：numberWithInt:       原型：+(NSNumber *)numberWithInt:(int)value;
2.创建和初始化实例方法
  形式：inttWithFloat:          原型：-(NSNumber *)initWithFloat:(float)value NS_DESIGNATED_INITIALIZER;
3.取值方法
  形式：intValue;    原型：@property (readonly) int intValue;
4.比较数字对象是否相等

形式：number1 isEqualToNumber:number2;

#import <Foundation/Foundation.h>int main(int argc, const char * argv[]) {    @autoreleasepool {               NSNumber *myNumber,*floatNumber,*intNumber;        NSInteger myInt;        //Integer值型        intNumber = [NSNumber numberWithInteger:100];        myInt = [intNumber integerValue];        NSLog(@"%li",(long)myInt);                //long型值                myNumber = [NSNumber numberWithLong:0xabcdef];        NSLog(@"%lx",[myNumber longValue]);                //char型值                        myNumber = [NSNumber numberWithChar:'X'];        NSLog(@"%c",[myNumber charValue]);                        //float型值                floatNumber = [NSNumber numberWithFloat:100.00];        NSLog(@"%g",[myNumber floatValue]);                        //double型值                myNumber = [NSNumber numberWithDouble:12345e+15];        NSLog(@"%lg",[myNumber doubleValue]);                //发生错误                        NSLog(@"%li",(long)[myNumber integerValue]);                        //验证两个Number是否相等        if ([intNumber isEqualToNumber:floatNumber]) {            NSLog(@"Numbers are equal");        }else{            NSLog(@"Numbers are not equal");                    }        //验证一个是否小于另一个数                if([intNumber compare: floatNumber] == NSOrderedAscending){            NSLog(@"First Number is less than second\n");        }            }    return 0;}

<span style="font-family: Arial, Helvetica, sans-serif;">//使用数字对象</span>

#import <Foundation/Foundation.h>int main(int argc, const char * argv[]) {    @autoreleasepool {        NSNumber *myNumber, *floatNumber,*intNumber;        NSInteger  myInt;        //整型integer        intNumber = @100;        myInt = [intNumber integerValue];        NSLog(@"%li",(long)myInt);                //长整型long value                myNumber = @0xabcdeL;        NSLog(@"%lx",[myNumber longValue]);                //字符型        myNumber = @'X';        NSLog(@"%c",[myNumber charValue]);            //浮点型                floatNumber = @100.0f;        NSLog(@"%g",[floatNumber floatValue]);        }    return 0;}

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