Develop Reference

How can I make a public "enemyDamage" integer from 1 script, communicate with another script?

I am new to coding and am not quite sure how to add context from 1 script to another. For my game so far, I have been Frankensteining code from multiple sources and have head into a dead end. I want my player to take the same amount of damage as stated by enemyDamage in the 'Enemy' script. I'm not too sure what other context to give you, but if you know how you could help me out, that would be awesome!
Enemy Script
using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using UnityEngine;
public class Enemy : MonoBehaviour
{
public int health = 100;
public int enemyDamage = 10;
public GameObject deathEffect;
public void TakeDamage (int damage)
{
health -= damage;
if (health <= 0)
{
Die();
}
}
void Die ()
{
Instantiate(deathEffect, transform.position, Quaternion.identity);
Destroy(gameObject);
}
}
PlayerHealth Script
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using UnityEngine;
public class PlayerHealth : MonoBehaviour
{
public int maxHealth = 10;
public int currentHealth;
public int damage = 1;
public HealthBar healthBar;
// Start is called before the first frame update
void Start()
{
currentHealth = maxHealth;
healthBar.SetMaxHealth(maxHealth);
}
// Update is called once per frame
void Update()
{
if (Input.GetKeyDown(KeyCode.R))
{
TakenDamage(1);
}
if (currentHealth <= 0)
{
PlayerDeath();
}
}
public void TakenDamage(int damage)
{
currentHealth -= damage;
healthBar.SetHealth(currentHealth);
}
void PlayerDeath()
{
UnityEngine.Debug.Log("bean guy");
}
public void OnTriggerEnter2D(Collider2D hitInfo)
{
UnityEngine.Debug.Log("We did it boys");
PlayerHealth player = hitInfo.GetComponent<PlayerHealth>();
{
UnityEngine.Debug.Log("beans");
TakenDamage(enemyDamage); // I need this to update with enemyDamage 's value
}
}
}

There are multiple ways:
Make EnemyDamage a Static Variable
public static int enemyDamage = 10;
Then you can call it in other scripts with Enemy.enemyDamage
Be aware that you can't set static variables in the Inspector.
Use GetComponent
Enemy enemy = gameObject.GetComponent(typeof(Enemy )) as Enemy;
enemy.enemyDamage
Create a GameManager
GameManager.CS:
#region Singelton
public static GameManager instance;
void Awake()
{
if (instance != null)
{
Debug.LogWarning("More than one Instance of Inventory found");
return;
}
instance = this;
}
#endregion
public int enemyDamage = 10;
Referencing the GameManager Script:
GameManager gm;
void Start()
{
gm = GameManager.instance;
}
//Calling Function in GameManager
gm.EndGame();
// Getting Value from GameManager
gm.enemyDamage();
When to use what?
If you want a more short term solution I would use a static variable, not advised with multiple enemies (different enemyDamage Values are now immosible)
If you have more variables or even functions that need to be accessible from multiple scripts I would advise you to use a Game Manager instead
You need to get a reference of the Enemy to use GetComponent, but makes it possible to add multiple different enemyDamage Values

Unity Sword Collision Attack

Hey guys I want to make a sword attack. But I get the error of:
NullReferenceException: Object reference not set to an instance of an
object
These are my codes:
My weaponattack script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Weaponattack : MonoBehaviour
{
Enemy Enemy;
public float power;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
}
public void OnTriggerEnter(Collider col)
{
if(col.tag == "Enemy")
{
var kılıc = GetComponent<Enemy>();
Enemy.currentHealt -= 10;
Enemy.TakeDamage();
Debug.Log("Düşman Vuruldu");
}
}
}
This is my Enemy Health scrpt:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Enemy : MonoBehaviour {
public float currentHealt;
public float maxHealth;
// Use this for initialization
void Start () {
currentHealt = maxHealth;
}
// Update is called once per frame
void Update () {
}
public void TakeDamage()
{
currentHealt -= 10;
if(currentHealt < 0)
{
die();
}
}
void die()
{
Destroy(gameObject);
}
}
Can you helo em I couldnt understan why these codes are not working why am I getting that error.

I think your problem is in this line here GetComponent<Enemy>(); This needs a game object to get the component of
Enemy = col.GetComponent<Enemy>();
Should be what you're doing
You also may have issue calling your variable Enemy exactly the same as your class Enemy, I would change this to Enemy enemy; and
enemy = col.GetComponent<Enemy>();
respectivley

It seems pretty straightforward. You don't assign an Enemy to Weaponattack and so it's barfing when you first reference Enemy (Enemy.currentHealt). Either make Enemy public or a SerializedField so you can assign it in the Inspector, or however else you want to get an Enemy into Weaponattack.
Also don't name your property the same name as your script (Enemy Enemy). Surprised you didn't get a compile error.
EDIT Based on comments:
Enemy enemy;
public void OnTriggerEnter(Collider col)
{
if(col.tag == "Enemy")
{
var kılıc = GetComponent<Enemy>();
kilic.currentHealt -= 10;
kilic.TakeDamage();
Debug.Log("Düşman Vuruldu");
}
}
This also assumes you have an Enemy attached to your Weaponattack (GetComponent)

Add float number to another script, c# unity [duplicate]

This question already has answers here:
What is a NullReferenceException, and how do I fix it?
(27 answers)
Closed 4 years ago.
I need help, i'am trying to add float number from a script to another script but it does not work. I'am new to c# and coding in general if somebody code fix the script and explained whats wrong with this i would be very thankful. This is the error i am getting.
"NullReferenceException: Object reference not set to an instance of an object
Resources.Die () (at Assets/Resources.cs:42)
Resources.Update () (at Assets/Resources.cs:22)"
Here is my scripts:
1st
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Resources : MonoBehaviour {
public float maxHealth = 5;
public float currentHealth;
public float ResourceCounter;
public Texture stoneIcon;
public Texture woodIcon;
void Start ()
{
currentHealth = maxHealth;
ResourceCounter = 0;
}
void Update ()
{
Die();
}
public void OnMouseOver()
{
if(Input.GetButtonDown("Fire1"))
{
Debug.Log("Loosing one health");
currentHealth = currentHealth - 1f;
}
}
public void Die()
{
if(currentHealth <= 0)
{
Destroy(gameObject);
Inventory inventory = GetComponent<Inventory>();
inventory.ResourceStone = inventory.ResourceStone + 1;
}
}
}
2nd
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Inventory : MonoBehaviour {
public float ResourceStone;
// Use this for initialization
void Start ()
{
ResourceStone = 0;
}
// Update is called once per frame
void Update () {
}
}

By looking at your code i think you never defined the inventory instance for your "resources" script. If you are using a getcomponent both the resources and the inventory script must be on the same gameobject to be found.
If what you want requires both scripts to be on other gameobjects you need a reference to the inventory in your resources script.
You can do this several way (like making a static reference and refering to it or defining inventory as a public variable and then adding the inventory reference in the unity editor)
This is how the first case would look:
First Script -
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Inventory : MonoBehaviour
{
public static Inventory instance;
private void Awake()
{
instance = this;
}
public float ResourceStone;
// Use this for initialization
void Start()
{
ResourceStone = 0;
}
}
Second Script -
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Resources : MonoBehaviour
{
public float maxHealth = 5;
public float currentHealth;
public float ResourceCounter;
public Texture stoneIcon;
public Texture woodIcon;
void Start()
{
currentHealth = maxHealth;
ResourceCounter = 0;
}
void Update()
{
Die();
}
public void OnMouseOver()
{
if (Input.GetButtonDown("Fire1"))
{
Debug.Log("Loosing one health");
currentHealth = currentHealth - 1f;
}
}
public void Die()
{
if (currentHealth <= 0)
{
Destroy(gameObject);
Inventory.instance.ResourceStone++;
}
}
}
This is how the code would look if you did the second one:
first script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Inventory : MonoBehaviour
{
public float ResourceStone;
// Use this for initialization
void Start()
{
ResourceStone = 0;
}
// Update is called once per frame
void Update()
{
}
}
second script-
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Resources : MonoBehaviour
{
public float maxHealth = 5;
public float currentHealth;
public float ResourceCounter;
public Inventory inventory;
public Texture stoneIcon;
public Texture woodIcon;
void Start()
{
currentHealth = maxHealth;
ResourceCounter = 0;
}
void Update()
{
Die();
}
public void OnMouseOver()
{
if (Input.GetButtonDown("Fire1"))
{
Debug.Log("Loosing one health");
currentHealth = currentHealth - 1f;
}
}
public void Die()
{
if (currentHealth <= 0)
{
Destroy(gameObject);
inventory.ResourceStone++;
}
}
}
Just take in account two things to decide if you will use the first or the second one. The first one is a static reference, that means that you can't make more that one inventory. In the second one you need to manually drag the reference in the editor. Just in case you don't know, writing ++ after an integer does the same as integer = integer + 1;
EDIT: There, that's better looking :D

Unity 5 An object reference is required for the non-static field, method, or property error

In Unity 5 using c# on line 35 of my PlayerMovement class I have this error:
Error CS0120 An object reference is required for the non-static field,
method, or property 'GameManager.completeLevel()'
PlayerMovement Class:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerMovement : MonoBehaviour {
public GameObject deathParticals;
public float moveSpeed;
private Vector3 spawn;
// Use this for initialization
void Start () {
spawn = transform.position;
moveSpeed = 5f;
}
// Update is called once per frame
void Update() {
transform.Translate(moveSpeed * Input.GetAxis("Horizontal") * Time.deltaTime, 0f, moveSpeed * Input.GetAxis("Vertical") * Time.deltaTime);
if (transform.position.y < -2)
{
Die();
}
}
void OnCollisionStay(Collision other)
{
if (other.transform.tag == "Enemy")
{
Die();
}
}
void OnTriggerEnter(Collider other)
{
if (other.transform.tag == "Goal")
{
GameManager.completeLevel();
}
}
void Die()
{
Instantiate(deathParticals, transform.position, Quaternion.identity);
transform.position = spawn;
}
}
GameManager Class:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class GameManager : MonoBehaviour {
public static int currentScore;
public static int highscore;
public static int currentLevel = 0;
public static int unlockedLevel;
public void completeLevel()
{
currentLevel += 1;
Application.LoadLevel(currentLevel);
}
}

As your GameManager class inherits from MonoBehaviour, this script needs to be attached to a game object. Then you need to get a reference to the the GameManager component, which can be done in several ways.
GameManager gameMananger = GameObject.Find("GameManager").GetComponent<GameManager>();
The above will work if your game object is called "GameManager", swap this for the name of your object if it is called something else.
Then gameMananger.completeLevel(); will now work.
You could shorten this to
GameObject.Find("GameManager").GetComponent<GameManager>().completeLevel();
If the GameManager script is attached to the same gameObject as PlayerMovement, this is all you need GetComponent<GameManager>().completeLevel();

You need to instantiate the GameManager object.
public GameObject gameManager;
Instantiate(gameManager)
Or as Jim mentioned:
you need to mark completeLevel as static:
static public void completeLevel()
{
....
}
More found here:
Unity Tutorial: gameManager

Identifier Expected error on 2D Collision Code?

I am trying to make a oncollision2D EnemyDamage is done removing health from playerStats.health, unfortunately I got the error, "Identifier expected" does anyone know what I need to put there to get the code to work? Thanks error on Collision (8,41).
Collision damage code:
using UnityEngine;
using System.Collections;
public class Collision : MonoBehaviour {
int EnemyDamage = 1;
void OnCollisionEnter2D(Collision2D)
{
playerStats.Health -= EnemyDamage;
}
}
Player Health Code:
using UnityEngine;
using System.Collections;
public class Player : MonoBehaviour {
[System.Serializable]
public class PlayerStats {
public int Health = 100;
}
public PlayerStats playerStats = new PlayerStats();
public int fallBoundary = -20;
void Update () {
if (transform.position.y <= fallBoundary)
DamagePlayer (9999999);
}
public void DamagePlayer (int damage) {
playerStats.Health -= damage;
if (playerStats.Health <= 0) {
GameMaster.KillPlayer(this);
}
}
}

Collision2D is a class and is used to return collision information when used with the OnCollisionEnter2D callback function. If you are going to use it, you have to put a variable after it.
void OnCollisionEnter2D(Collision2D)
{
}
should be
void OnCollisionEnter2D(Collision2D col)
{
playerStats.Health -= EnemyDamage;
}
If you don't need to get information about the collison, you can just use the OnCollisionEnter2D function without Collision2D parameter at-all.
void OnCollisionEnter2D()
{
playerStats.Health -= EnemyDamage;
}