//1,
NSString *name = [[NSString alloc]initWithString:@"张三"];
NSLog(@"%d",[name retainCount]);
//2014-11-27 20:43:20.290 OC考试错题[1750:303] -1
//2,
NSString* testObject = [[NSData alloc] init];
//编译时，NSString类型，运行时，NSData类型
//3,
NSArray *(^aBlock)(NSString * str,NSString *str2);
//声明一个返回值为NSArray，并且带两个字符串对象的BLOCK类型变量
//4,
NSMutableDictionary * dic = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"1",@"2",@"2",@"3",@"3",@"4", nil];
NSArray *arr = [[NSArray alloc] initWithArray:[dic allKeys]];
NSString *str = [[NSString alloc] initWithFormat:[arr objectAtIndex:0],[arr objectAtIndex:1],[arr objectAtIndex:2]];
NSLog(@"%@",str);
//2014-11-27 20:47:22.678 OC考试错题[1761:303] 2
//5,
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSString *sstr = [NSString stringWithFormat:@"abc"];
NSString *str2 = [sstr retain];
[pool release];
NSLog(@"sstr retainCount = %ld,str2 retainCount = %ld",[sstr retainCount],[str2 retainCount]);
// sstr retainCount = 1,str2 retainCount = 1
//6,
NSMutableDictionary * dic1 = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"1",@"2",@"1",@"3",@"1",@"4", nil];
NSArray *arr1 = [[NSArray alloc] initWithArray:[dic1 allKeys]];
NSArray *arr2 = [[NSArray alloc] initWithArray:[dic1 allValues]];
NSMutableDictionary *dic2 = [[NSMutableDictionary alloc] initWithObjects:arr1 forKeys:arr2];
NSLog(@"%@",dic2);
// 1 = 4;
//7,将@”2B青年”替换成@”文艺青年”
NSRange range1 = {0,2};
[@"2B青年" stringByReplacingCharactersInRange:range1 withString:@"文艺"];
//8,
NSMutableDictionary * dic3 = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"1",@"2",@"2",@"3",@"3",@"4", nil];
[dic3 setObject:@"1" forKey:@"3"];
[dic3 removeObjectForKey:@"1"];
NSLog(@"%@",dic3);
// 2 = 1;3 = 1;4 = 3;
//9,在类方法中bu可以使用实例变量。
//10,实例对象都是通过调用类方法生成的。
return 0;