How do I get the player to collide with another object to use as a boundary?

Question

I'm trying to make a simple game where you move a sphere from left/right and try to avoid falling cubes. If a cube touches the player (sphere), the player dies. I'm trying to set up boundaries using a cylinder with a collider, but every time I hit the collider boundary, the player disappears like they would if they hit a cube. Here is my player script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;

public class Move : MonoBehaviour
{
public float moveSpeed = 1;

// Start is called before the first frame update
void Start()
{

}

// Update is called once per frame
void Update()
{

    transform.position += new Vector3(Input.GetAxis("Horizontal") * moveSpeed, 0, 0);
}

void OnCollisionEnter(Collision collision)
{
    if (collision.gameObject.tag == "Cube")
    {
        Destroy(collision.gameObject);
        Destroy(gameObject);
    }
}

}

Answer 1

To make the if condition apply to both lines, put braces around them like this:

void OnCollisionEnter(Collision collision)
{
    if (collision.gameObject.tag == "Cube")
    {
        Destroy(collision.gameObject);
        Destroy(gameObject);
    }
}

Note: get in the habit of always using braces with if-, while-, and for-statements to make it explicitly clear what lines the statement applies to.