Moving objects into random places by using functions-CodePudding

I'm writing a code of moving a object to random places. I made a function which decides the random coordinates and returns it. However, I think the function and is not connected together. This is what I tried...

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

public class Movement : MonoBehaviour
{

    public float speed;

    Vector3 target;

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

    // Update is called once per frame
    void Update()
    {
        Vector3 target = random(target);
        transform.position = Vector3.MoveTowards(transform.position, target, Time.deltaTime * speed);
    }

    Vector3 random(Vector3 target)
    {
        float min = -100.0f;
        float max = 100.0f;
        float randomX = Random.Range(min, max);
        float randomZ = Random.Range(min, max);
        Vector3 target = new Vector3(randomX, 10.0f, randomZ);

        return target;
    }

}

And this is the error message I got.

Assets\Movement.cs(31,17): error CS0136: A local or parameter named 'target' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter

How can I fix this?

CodePudding user response：

The problem is you define a new target variable inside random method. You have defined it as argument in method body before. Change one of them.

CodePudding user response：

It is not really a problem with unity but with compiler.

Inside the random(Vector3 target) and void Update() methods you are defining new "target" variables like this:

Vector3 target

so the compiler is telling you that this is not allowed. If you want to update the target variable then remove the "Vector3" infront or choose a new name.

It is not clear how this function is meant to work but I think it is good to declare the target on start or declare it public so you can assign a start position to it.

I think what you want is something like this:

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

public class Movement : MonoBehaviour
{

    public float speed;

    // OPTIONAL: declare public so the editor will let you set a position
    public Vector3 target;

    // Start is called before the first frame update
    void Start()
    {
        // OPTIONAL: you can set a start position
        target = Vector3.zero;
    }

    // Update is called once per frame
    void Update()
    {
        target = random(target);
        transform.position = Vector3.MoveTowards(transform.position, target, Time.deltaTime * speed);
    }

    Vector3 random(Vector3 par)
    {
        float min = -100.0f;
        float max = 100.0f;
        float randomX = Random.Range(min, max);
        float randomZ = Random.Range(min, max);
        return new Vector3(randomX, 10.0f, randomZ);
    }

EDIT: You do not really need a parameter to the "random" function now. So maybe you can remove it

CodePudding user response：

The reason you are getting this error is because you have already declared Vector3 target as a class member outside of the random and update methods.

If you are coming from a language like JavaScript, you can do it by declaring the same var variable name inside an inner scope but in C# it's not possible.