Object -C NSNumber -- 笔记

//

//  main.m

//  NSNumber

//

//  Created by facial on 24/8/15.

//  Copyright (c) 2015 facial_huo. All rights reserved.

//

 

#import <Foundation/Foundation.h>

 

int main(int argc, const char * argv[]) {

    @autoreleasepool {

        // insert code here...

        NSLog(@"Hello, World!");

        

        NSNumber *intNumber = [[NSNumber alloc] initWithInt: 1];

        NSNumber *floatNumner = [[NSNumber alloc] initWithFloat:1.0f];

        NSNumber *doubleNumber = [[NSNumber alloc] initWithDouble: 3.33];

        NSNumber *charNumber = [[NSNumber alloc] initWithChar: 'A'];

        

        //比较数字大小

        NSNumber *intNumber2 = [[NSNumber alloc] initWithInt:2];

        bool ret = [intNumber2 isEqualToNumber: intNumber];  // intNumber = 1, intNumber = 2. so ret = 0;

        NSLog(@"%d",ret);

        

        

        //比较float and int

        bool ret2 = [intNumber isEqualToNumber: floatNumner];

            // int intBumber = 1, floatNumber = 1.0f, so ret2 = 0;

        

        //比较

        

        NSNumber *num1 = [[NSNumber alloc] initWithInt: 10 ];

        NSNumber *num2 = [[NSNumber alloc] initWithInt: 10 ];

        

        

        if( [num1 compare:num2] == NSOrderedAscending  ) {

            NSLog(@" < ");

        }else if([num1 compare:num2] == NSOrderedDescending) {

            NSLog(@">");

        }else if ([num1 compare:num2] == NSOrderedSame){

            NSLog(@"==");

        }

        

        // 把NSNumber 类型转回去普通的类型

        NSLog(@"%d", [intNumber intValue]);

        NSLog(@"%f", [floatNumner floatValue]);

        NSLog(@"%f", [doubleNumber doubleValue]);

        NSLog(@"%c", [charNumber charValue]);

 

 

        

        

        

        

        

 

        

        

        

        

        

    }

    return 0;

}