Error CS0131: The left-hand side of an assignment must be a variable, property or indexer.

Unity Engine
1

I have been programming a script to make the movement of an object when it is touched by a player and that when it stops touching it it stops moving. But I have this error.

This is the script:

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

public class LogicaCaja : MonoBehaviour
{
    public float speed;
    public float maxSpeed;
    public bool istouching;

    private Rigidbody2D rb2d;

    void Start()
    {
        rb2d = GetComponent<Rigidbody2D>();
    }

    void Update()
    {
    
    }

    void OnCollisionEnter2D(Collision2D col)
    {
        if(col.gameObject.tag == "Player" && istouching = true)
        {
           rb2d.AddForce(Vector2.right * speed);
        }

        if (rb2d.velocity.x > maxSpeed)
        {
            rb2d.velocity = new Vector2(maxSpeed, rb2d.velocity.y);
        }

        if (rb2d.velocity.x < -maxSpeed)
        {
            rb2d.velocity = new Vector2(-maxSpeed, rb2d.velocity.y);
        }
    }

    void OnCollisionExit2D(Collision2D col)
    {
        if (col.gameObject.tag == "Player")
        {
            istouching = false;
            rb2d.velocity = new Vector2(rb2d.velocity.x, rb2d.velocity.y);
        }
    }
}
2

7345100--893435--upload_2021-7-20_16-44-36.png
7345100--893435--upload_2021-7-20_16-44-36.png1920×1080 161 KB

3

You can simply use code-tags when posting code (no need to post plain-text or images of code or both). You can also go back and just edit your first post too to include them.

If you are reporting an error, report it in full including the line/column number reported with it and if it’s not identical to the code you’re posting then indicate which line it is.

You can also look up the error with Google which is easy to do. To be honest, the error is pretty self explanatory. You need to assign whatever it is you’re assigning to what it says, a variable, property or indexer. It might be that on the line/column is actually gives you, you didn’t mean to assign anything which I think is the case here.

I can see you typed “istouching = true” but presume you mean to use “==”.

4

Hello again, thanks for helping me. If I use the comparer “==” it gives another error.

This is the new error:

Assets\Scripts\LogicaCaja.cs(45,13): error CS0201: Only assignment, call, increment, decrement, await, and new object expressions can be used as a statement

This is the error exactly if i dont use “==”: Assets\Scripts\LogicaCaja.cs(25,12): error CS0131: The left-hand side of an assignment must be a variable, property or indexer

5

I don’t see why you’d get that by replacing the assignment operator = with the comparer operator ==

These are just basic typos in C# nothing to do with Unity really. Just check your syntax and look carefully at the line/column it tells you.

6

Hold on, this is a different line? On that line you want to assign the value true not check the value if it’s true. Nobody said to change that line. I was referring to line 25.

Is this your code? Are you just guessing at what this code does? I’m confused.

This is why you should always report the full error including the line/column numbers.

7

I will also ask again; please edit your post to include code-tags.

8

It is already solved, thank you for your attention.

9

I’ve gone ahead and edited your post to use code-tags.

10

Ok thaks for the advice

11

I just have one more question, why when I start the game does the box slide little by little? Everything works fine except that. In the script I set the speed at the beginning to be 0.

12

I don’t really know the context, maybe try increasing the linear drag on the rigidbody.

13

Thanks man, I solvet it

14

i have the same error but i don’t think the solution is the same because its pointing me towards line 37 in this code

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

public class PlayerController : MonoBehaviour
{
    public float moveSpeed = 1f;

    public float collisionOffset = 0.05f;

    public ContactFilter2D movementFilter;

    Vector2 movementInput;

    Rigidbody2D rb;

    List<RaycastHit2D> castCollisions = new List<RaycastHit2D>();
    // Start is called before the first frame update
    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    private void Fixedupdate()
    {
        if(movementInput != Vector2.zero)
        {
            int count = rb.Cast(
                movementInput,
                movementFilter,
                castCollisions,
                moveSpeed = Time.fixedDeltaTime = collisionOffset);
            if(count == 0)
            {
                rb.MovePosition(rb.position * movementInput * moveSpeed = Time.fixedDeltaTime);
            }
        }
    }
  

    void OnMove(InputValue movementValue)
    {
        movementInput = movementValue.Get<Vector2>();
    }
}
15

Well please create your own thread then. Don’t hijack someone elses typo thread for your own typo thread.

Also, please post scripting questions on the scripting forum.

Thanks.