Access variable from different class

Questions & Answers
1

I am making a power up for my player to double up its speed if it enter’s the power up prefab’s Collider .
There are no errors popping up but when i enter the collider of the power up prefab still there is no change in the speed . check my code and help me out to spot the error . Any help is appreciated.

using UnityEngine;
using System.Collections;

public class Movement : MonoBehaviour{
	public float movespeed= 12f;
	public  float turnspeed = 130f;

	    void Update () {
		if (Input.GetKey (KeyCode.UpArrow)) {
			transform.Translate (Vector3.forward * movespeed * Time.deltaTime);
		}
		if(Input.GetKey (KeyCode.DownArrow)) {
			transform.Translate(-Vector3.forward * movespeed * Time.deltaTime);   
		}
		if(Input.GetKey (KeyCode.LeftArrow)) {
			transform.Rotate(Vector3.up * -turnspeed * Time.deltaTime);          
		}
		if(Input.GetKey (KeyCode.RightArrow)) {
			transform.Rotate(Vector3.up * turnspeed * Time.deltaTime);          
		}

	}
}

Power up code

using UnityEngine;
using System.Collections;

public class Powerup : MonoBehaviour {

	private Vector3 orginalscale;
	protected Collider collider;

	public float rotation_speed =50f;
	public float up_down_speed =0.3f;

	private float speedMultiplier = 2.0f;

	private Movement movement ;

	void Start () {

		orginalscale = transform.localScale;
		collider = GetComponent<Collider>();

		}
	

	void Update () {
		transform.Rotate(new Vector3 (0, Time.deltaTime * rotation_speed, 0));
		Vector3 position = transform.position;
		position.y -= Mathf.Sin(Time.timeSinceLevelLoad - Time.deltaTime) * up_down_speed;
		position.y += Mathf.Sin(Time.timeSinceLevelLoad) * up_down_speed;
		transform.position = position;

		}
	    void OnTriggerEnter(Collider other) {
		collider.enabled = false;
		transform.localScale = Vector3.zero;
		GameObject thePlayer = GameObject.Find("enemytank1");
		movement=thePlayer.GetComponent< Movement>();
		movement.movespeed *= speedMultiplier;
		
		}

}
2

@Aj_112 I assume you can call the triggers fine.

void OnTriggerEnter(Collider other) {
             collider.enabled = false;
             transform.localScale = Vector3.zero;
            
             //GameObject thePlayer = GameObject.Find("enemytank1");
             //movement=thePlayer.GetComponent< Movement>();
            // movement.movespeed *= speedMultiplier;
             if(other.gameObject.tag == "player"){
                   other.gameObject.GetComponent<Movement>().movespeed *= speedMultiplier;
             }
   }

Just create a new tag called “player” and set that tag on the player object which has the Movement script attached to it. Once you pass through the trigger, the player speed should be doubled by speedMultiplier, keep in mind the speed is not going to decrease back to normal unless you specify otherwise. I don’t know if this code will work though.