数字对象NSNumber

//将int类型转化成对象
int number = ;
NSNumber *numberString = [NSNumber numberWithInt:number];
//对象是可以放入数组的
NSArray *array = [NSArray arrayWithObject:numberString];
//转回来
int number2 = [numberString intValue];

//字符串转整型
NSString *string3 = @"";
int number3 = [string3 intValue];
//整型转字符串
int number4 = ;
NSString *string4 = [NSString stringWithFormat:@"%d",number4];