NSMutableArray

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSString *str1 = @"zhangsan" ;
        NSString *str2 = @"lisi" ;
        NSString *str3 = @"wangwu" ;
        
        //可变数组的创建
        NSMutableArray *array1 = [[NSMutableArray alloc]initWithObjects:str1, str2 , str3 , nil ] ;
        NSLog(@"array1 = %@",array1);
        
        //开辟五个内存空间 用于存储元素 当数组元素超过时 会自动增大空间
        NSMutableArray *array2 = [[NSMutableArray alloc]initWithCapacity:5];
        /*
         //使用类方法创建
        NSMutableArray *array2 = [NSMutableArray arrayWithCapacity:5];
         */
        
        //添加元素
        [array1 addObject:str1];
        [array1 addObject:str2];
        
        //添加数组 把array1 中的所有元素都添加到array2 中
        [array2 addObjectsFromArray:array1];
        NSLog(@"array2 = %@",array2);
        
        /*
        //二维数组 将array2变成二维数组
        [array2 addObject:array1];
        NSLog(@"array2 =  %@",array2);
         */
        
        //在指定位置加入元素
        [array2 insertObject:@"maliu" atIndex:2];
        NSLog(@"array2 = %@",array2);
        
        //替换元素
        [array2 replaceObjectAtIndex:0 withObject:@"999"];
        NSLog(@"array2 = %@",array2);
        
        //互换位置
        [array2 exchangeObjectAtIndex:1 withObjectAtIndex:2] ;
        NSLog(@"array2 = %@",array2);
        
        //删除元素的位置
        [array2 removeObjectAtIndex:0];
        NSLog(@"array2 = %@",array2);
        //删除指定对象 所有
        [array2 removeObject:@"lisi"];
        NSLog(@"array2 = %@",array2);
        //删除最后一个对象
        [array2 removeLastObject];
        NSLog(@"array2 = %@",array2);
        //对数组对象进行排序
        [array2 sortUsingSelector:@selector(compare:)];
        NSLog(@"a = %@",array2);
        
        //删除所有对象
        [array2 removeAllObjects];
        NSLog(@"array2 = %@",array2);
        
    }
    return 0;
}