OC -- NSNumber

// 定义NSNumber的方法1:
NSNumber *intNumber = [[NSNumber alloc] initWithInt:5];
NSNumber *floatNumber = [[NSNumber alloc] initWithFloat:3.15f];
NSNumber *doubleNumber = [[NSNumber alloc] initWithDouble:6.8];
NSNumber *charNumber = [[NSNumber alloc] initWithChar:‘A‘];
// 定义NSNumber的方法2:
NSNumber *intNumber2 = [NSNumber numberWithInt:6];
// 判断两个NSNumber是否相等
BOOL ret = [intNumber isEqualToNumber: intNumber2];
// 比较两个NSNumber的大小
if([intNumber compare: intNumber2] == NSOrderredAscending){
    NSLog(@"<");
}else if([intNumber compare: intNumber2] == NSOrderedSame){
    NSLog(@"=");
}else if([intNumber compare: intNumber2] == NSOrderedDescending){
    NSLog(@">");
}
// 还原基本类型数据
NSLog(@"%d", [intNumber intValue]);
NSLog(@"%f", [floatNumber floatValue]);
NSLog(@"%f", [doubleNumber doubleValue]);
NSLog(@"%c", [charNumber charValue]);