创建三个字符串对象
NSString *apple = [[NSString alloc] initWithFormat:@"apple"];
NSString *meiZu = [[NSString alloc] initWithFormat:@"MeiZu"];
NSString *xiaoMi = [[NSString alloc] initWithFormat:@"XiaoMi"];
//NSArray
//initWithObject: 方法, 需要传入多个对象,这些对象之间","隔开 最后以nil结尾
//!!!!! nil之后的对象不再存入数组
NSArray *array = [[NSArray alloc] initWithObjects:apple,meiZu,xiaoMi, nil];
NSLog(@"%@",array);
//通过下标找到对象
NSString *who = [array objectAtIndex:1];
NSLog(@"%@",who);
//通过对象获取下标
//只会找到第一个符合对象的下标 并返回
NSInteger index = [array indexOfObject:xiaoMi];
NSLog(@"%ld",index);
//数组元素个数
NSInteger count = [array count];
NSLog(@"%ld",count);
//遍历
for (int i = 0; i < array.count; i ++) {
NSLog(@"%@",[array objectAtIndex:i]);
}
//排序
NSArray *sortedArr = [array sortedArrayUsingSelector:@selector(compare:)];
NSLog(@"%@",sortedArr);
//NSMutableArray
//创建可变数组对象
NSMutableArray *mutableArray = [[NSMutableArray alloc] initWithObjects:apple,xiaoMi, nil];
//添加
[mutableArray addObject:meiZu];
NSLog(@"%@",mutableArray);
//删除
//移除对应下标的对象
[mutableArray removeObjectAtIndex:2];
NSLog(@"%@",mutableArray);
[mutableArray addObject:meiZu];
[mutableArray addObject:meiZu];
[mutableArray addObject:meiZu];
NSLog(@"%@",mutableArray);
//removeObject: 会将符合条件的对象全部删除
[mutableArray removeObject:meiZu];
NSLog(@"%@",mutableArray);
//交换
[mutableArray exchangeObjectAtIndex:1 withObjectAtIndex:0];
NSLog(@"%@",mutableArray);
//排序
NSString *str1 = @"aa";
NSString *str2 = @"bb";
NSString *str3 = @"cc";
NSString *str4 = @"dd";
NSString *str5 = @"ee";
NSMutableArray *arr = [[NSMutableArray alloc] initWithObjects:str3,str5,str1,str4,str2, nil];
NSLog(@"%@",arr);
for (int i = 0; i < arr.count - 1; i ++) {
for (int j = 0; j < arr.count - i - 1; j ++) {
//获取数组元素
NSString *a = [arr objectAtIndex:j];
NSString *b = [arr objectAtIndex:j + 1];
if ([a compare:b] > 0) {
//通过下标进行数组元素的交换
[arr exchangeObjectAtIndex:j withObjectAtIndex:j + 1];
}
}
}
[arr sortUsingSelector:@selector(compare:)];
NSLog(@"%@",arr);
//获取第一个对象
[arr firstObject];
//获取最后一个
[arr lastObject];