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;

}