NSNumber(封裝基本數據類型)

    //

    //  main.m

    //  OC05-task-04

    //

    //  Created by Xin the Great on 15-1-26.

    //  Copyright (c) 2015年 Xin the Great . All rights reserved.

    //


#import <Foundation/Foundation.h>  

int main(int argc, const charchar * argv[]) {  
    @autoreleasepool {  
        // insert code here...  

        //////////////////////NSNumber//////////////////////  
        //封裝基本數據類型  

        int intValue = 100;  
        float floatValue = 3.14;  
        BOOL boolValue = YES;  

        NSNumber *intNumber = [[NSNumber alloc] initWithInt:intValue];  
        NSLog(@"intNumber is %@", intNumber);  
        NSNumber *floatNumber = [NSNumber numberWithFloat:floatValue];  
        NSLog(@"floatNumber is %@", floatNumber);  
        NSNumber *boolNumber = [NSNumber numberWithBool:boolValue];  
        NSLog(@"boolNumber is %@", boolNumber);  

        //包裝之后就可以放到容器中  
        NSArray *arr = @[intNumber, floatNumber, boolNumber];  
        NSLog(@"arr is %@", arr);  


        //還原成基本數據類型  
        float value = [floatNumber floatValue];  
        int value2 = [intNumber intValue];  
        NSLog(@"value is %.2f",value);  
        NSLog(@"value2 is %d",value2);  


        //快速創建的方法  
        NSNumber *intNum = @80;//---->  NSNumber *intNumber = [[NSNumber alloc] initWithInt:80];  

        NSNumber *floatNum = @3.14;// ---->[NSNumber numberWithFloat:3.14];  

        NSNumber *boolNum = @YES;// ---> [NSNumber numberWithBool:YES];  

        NSNumber *charNum = @'a'; // ---> [NSNumber numberWithChar:'a'];  


        //運算  
        NSNumber *number = @(1 + 2);  

        //直接在數組中寫  
        NSArray *arr1 = @[@"string", @12, intNum, floatNum, boolNum, charNum, number];  
        NSLog(@"arr1 is %@", arr1);  

    }  
    return 0;  
}  </pre> 


 來自：http://blog.csdn.net/zuojx1013/article/details/43202413