//1)创建一个空数组
NSArray *arr1 = [NSArray array];
//2)创建数组,只有一个元素
NSArray *arr2 = [NSArray arrayWithObject:@"1"];
//4)调用对象方法,创建数组
//nil Nil NULL NSNULL
NSArray *arr4 = [[NSArray alloc] initWithObjects:@"three",[NSNull null],@"four", nil];
NSLog(@"arr4 = %@",arr4);
NSArray *arr3 = [NSArray arrayWithObjects:@"one",@"two",@1,@"three", nil];
NSLog(@"arr3 = %@",arr3);
//1)获取数组的长度 count获取数组的元素的个数
NSLog(@"%ld", [arr3 count]);
//2)根据下标,获取下标对应的对象
NSLog(@"%@",[arr3 objectAtIndex:3]);
//3)返回元素的下标(首个)
NSUInteger loc = [arr3 indexOfObject:@"three"];
NSLog(@"%ld",loc);
//4)数组中是否包含了某个元素
if([arr3 containsObject:@"four"]){
NSLog(@"包含此元素");
}else{
NSLog(@"不包含");
}
NSMutableArray *mutableArray = [NSMutableArray array];
[mutableArray addObject:@"fuck"];
[mutableArray addObjectsFromArray: arr3];
[mutableArray removeObject: @"three"];
for (NSString *str in mutableArray) {
NSLog(@"%@", str);
}
// //枚举器遍历数组
// NSEnumerator *myEnumerator = [arr3 objectEnumerator];
// id temp;
// while (temp = myEnumerator.nextObject) {
// NSLog(@"%@", temp);
// }
// //普通for循环遍历数组
// for (int i = 0; i < [arr3 count]; ++i) {
// NSLog(@"%@", arr3[i]);
// }
// //for循环快速枚举遍历数组
// for (NSString *str in arr3) {
// NSLog(@"%@", str);
// }
//创建一个空的字典
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
NSMutableDictionary *dict2 = [NSMutableDictionary dictionaryWithDictionary:dict];
NSMutableDictionary *dict3 = [NSMutableDictionary dictionaryWithObject: @"wangziyou" forKey:@"wzy"];
[dict addEntriesFromDictionary:dict3];
[dict removeObjectForKey:@"wzy"];
[dict setObject:@"fuckyou" forKey:@"fy"];
[dict setObject:@"wutingting" forKey:@"wzy"];
NSLog(@"%@", dict);