OC-数组类

NSArray

创建一个不可变数组对象

NSMutableArray

创建可变数组对象

数组中的元素都是对象可以是任意类型的对象

/*数组中存放的对象的引用*/

/* 数组的初始化方法 ：NSArray 创建的数组不能被修改*/

1.OC中的数组初始化

包括类方法初始化和对象方法初始化两种方式：

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //直接创建一个常量数组
        NSArray *array1 = @[@"one",@"two",@"three"];
        NSLog(@"array1 = %@",array1);
        
        /*
         OC中的数组类似于C语言中的指针数组，但是指针数组只能同一类型的，而OC中的数组可以是任意类型的
         */
        //用不同对象来初始化数组
        NSArray *array2 = [[NSArray alloc]initWithObjects:@"hello world", [NSNumber numberWithInt:123],[NSDate date],[NSNumber numberWithFloat:3.14],nil];
        NSLog(@"array2 = %@",array2);
        
        //用其他已经存在的数组来创建数组
        NSArray *array3 = [[NSArray alloc]initWithArray:array1];
        NSLog(@"array3 = %@",array3);
        
        //copyItems:拷贝一份
        //copyItems:直接return
        NSArray *array4 = [[NSArray alloc]initWithArray:array2 copyItems:YES];
        NSLog(@"array4 = %@",array4);
        
        //类方法
        //创建一个空的数组对象
        NSArray *array5 = [NSArray array];
        NSLog(@"array5 = %@",array5);
        
        //多个对象创建一个数组
        NSArray *array6 = [NSArray arrayWithObjects:@"one",@"two",[NSNumber numberWithFloat:3.14],nil];
        NSLog(@"array6 = %@",array6);
        
        //用已经存在的数组创建数组
        NSArray *array7 = [NSArray arrayWithArray:array6];
        NSLog(@"array7 = %@",array7);
    }
    return 0;
}

2.OC数组的操作函数

int main(int args,const char *argv[])
{
    @autoreleasepool {
        NSArray *array1 = [[NSArray alloc]initWithObjects:@"123",@"abc",@"oop", nil];
        NSLog(@"array1 = %@",array1);
        
        //计算数组的长度
        NSInteger count = [array1 count];
        NSLog(@"count = %ld",count);
        
        //获取指定位置的对象
        id obj = [array1 objectAtIndex:2];
        NSLog(@"obj = %@",obj);
        
        //在数组中添加一个对象：其实是在底层中生成一个新的数组对象
        NSArray *array2 = [array1 arrayByAddingObject:@"alibb"];
        NSLog(@"array2 = %@",array2);
        
        //将传入的数组添加到一个数组的末尾
        NSArray *otherArray = [[NSArray alloc]initWithObjects:@"add",@"sub",@"mul",@"div", nil];
        NSArray *array3 = [array1 arrayByAddingObjectsFromArray:otherArray];
        NSLog(@"array3 = %@",array3);
        
        //用指定字符串连接数组元素
        NSLog(@"array1 = %@",array1);
        NSString *str = [array1 componentsJoinedByString:@"##"];
        NSLog(@"str = %@",str);
        
        //判断是否包含对象
        BOOL flag = [array1 containsObject:@"oop"];
        NSLog(@"flag = %i",flag);
        
        //返回两个数组中第一个公共的对象
        id obj2 = [array1 firstObjectCommonWithArray:otherArray];
        NSLog(@"obj2 = %@",obj2);
        
        
        //返回数组中第一次出现的下标位置
        NSArray *array4 = [[NSArray alloc]initWithObjects:@"add",@"sub",@"mul",@"zjl",@"mul",@"div", nil];
        NSUInteger index = [array4 indexOfObject:@"mul"];
        NSLog(@"index = %lu",index);
        //在数组的指定范围内查找第一次出现的对象，并返回下标
        NSUInteger indexRange = [array4 indexOfObject:@"mul" inRange:NSMakeRange(3, 3)];
        NSLog(@"index2 = %lu",indexRange);
        
        //判断两个数组是否相等
        BOOL flag1 = [array1 isEqualToArray:array4];
        NSLog(@"flag1 = %i",flag1);
        
        //获取数组中的第一个元素
        id obj3 = [array4 firstObject];
        NSLog(@"obj3 = %@",obj3);
        
        //获取数组中的最后一个元素
        id obj4 = [array4 lastObject];
        NSLog(@"ojb4 = %@",obj4);
        
        
        //重要：数组的遍历   有三种方法
        //1.下标法
        NSArray *array5 = @[@"one",@"two",@"three",@"foure",@"five"];
        NSUInteger len = [array5 count];
        for (int i=0; i<len; i++) {
            NSLog(@"array5[%i] = %@",i,[array5 objectAtIndex:i]);
        }
        //2.枚举器法
        NSEnumerator *enumerator = [array5 objectEnumerator]; //生成枚举器对象
        //通过枚举器对象来遍历对象
        id item = nil;
        while (item = [enumerator nextObject]) {
            NSLog(@"%@",item);
        }
        //通过枚举器法反向变量数组
        NSEnumerator *reverseEnumerator = [array5 reverseObjectEnumerator];
        id item1 = nil;
        while (item1 = [reverseEnumerator nextObject]) {
            NSLog(@"item1 = %@",item1);
        }
        //3.快速枚举法  //速度最快
        for (id item2 in array5) {
            NSLog(@"item2 = %@",item2);
        }
        
        //数组排序，通过选择器
        NSArray *array6 = @[@"one",@"two",@"three",@"four",@"five"];
        NSArray *array7 = [array6 sortedArrayUsingSelector:@selector(compare:)];
        NSLog(@"array7 = %@",array7);
        
        //数组提取
        NSArray *array8 = [array6 subarrayWithRange:NSMakeRange(1, 3)];
        NSLog(@"array8 = %@",array8);
        
        
        //通过对象下标集合获取指定的数组对象
        //创建一个下标集合
        NSMutableIndexSet *indexSet = [[NSMutableIndexSet alloc] initWithIndex:0];
        [indexSet addIndex:2];
        [indexSet addIndex:4];
        [indexSet addIndex:0];
        //通过对象下标集合获取指定的数组对象
        NSArray *array9 = [array6 objectsAtIndexes:indexSet];
        NSLog(@"array9 = %@",array9);
    }
}

3.OC可变数组的操作函数(特有的)

int main(int args,const char *argv[])
{
    @autoreleasepool {
        NSMutableArray *mulArray = [[NSMutableArray alloc] initWithCapacity:20];
        NSMutableArray *mulArray1 = [NSMutableArray arrayWithCapacity:20];
        
        
        [mulArray addObject:@"one"];
        NSLog(@"mulArray = %@",mulArray);
        
        //指定位置中插入对象
        [mulArray insertObject:@"two" atIndex:1];
        NSLog(@"mulArray = %@",mulArray);
        
        //将给定的数组插入到可变数组末尾
        [mulArray addObjectsFromArray:@[@"123",@"567",@"890"]];
        NSLog(@"mulArray = %@",mulArray);
        
        //删除数组最后一个元素
        [mulArray removeLastObject];
        NSLog(@"mulArray = %@",mulArray);
        
        //从数组删除指定对象
        [mulArray removeObject:@"123"];
        NSLog(@"mulArray = %@",mulArray);
        
        //删除数组中指定位置的元素
        [mulArray removeObjectAtIndex:1];
        NSLog(@"mulArray = %@",mulArray);
        
        //替换指定位置的元素
        [mulArray replaceObjectAtIndex:0 withObject:@"five"];
        NSLog(@"mulArray = %@",mulArray);
        
        //交换两个位置的元素
        [mulArray exchangeObjectAtIndex:0 withObjectAtIndex:1];
        NSLog(@"mulArray = %@",mulArray);
        
        [mulArray addObjectsFromArray:@[@"aaa",@"ccc",@"bbb",@"ccc",@"ddd",@"eee",@"fff"]];
        
        //在指定范围内删除指定对象
        [mulArray removeObject:@"567" inRange:NSMakeRange(0, 1)];
        NSLog(@"mulArray = %@",mulArray);
        
        //删除数组中指定的所有对象
        [mulArray removeObject:@"ccc"];
        NSLog(@"mulArray = %@",mulArray);
        
        //删除所有在传入数组中出现的元素
        [mulArray removeObjectsInArray:@[@"aaa",@"bbb",@"888"]];
        NSLog(@"mulArray = %@",mulArray);
        
        //删除所有在指定范围内的元素
        [mulArray removeObjectsInRange:NSMakeRange(1, 2)];
        NSLog(@"mulArray = %@",mulArray);
        
        
        //用给定的数组 修改数组(重置)数组
        [mulArray setArray:@[@"123",@"345",@"567",@"789"]];
        NSLog(@"mulArray = %@",mulArray);
        
        
        //数组排序
        NSMutableArray *sortArray = [NSMutableArray array];
        [sortArray sortUsingSelector:@selector(compare:)];
        NSLog(@"sortArray = %@",sortArray);
        
        
        //用传入的数组替换指定范围内的数组元素
        //用传入的数组替换指定范围内的数组元素
        [mulArray replaceObjectsInRange:NSMakeRange(0, 2) withObjectsFromArray:@[@"one",@"two",@"three"]];
        NSLog(@"mulArray = %@", mulArray);
    }
}