Object reference not set to an instance of an object error

UNity Novice here.

I have a working game to add two numbers and then show the answer on screen, It works just fine with this script.

[script]
using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class NumberLine : MonoBehaviour {

public InputField number1;
public InputField number2;
public Slider numberLine;
public Text coordinate;
public GameObject spawner;
public Canvas c;

//public Button calc;
private int result = 0;
private int n1 = 0;
private int n2 = 0;
public Text results;
// Use this for initialization


// Update is called once per frame
void Update () {
result = n1 + n2;
//string r = result.ToString();
Debug.Log(result.ToString());
results.text = result.ToString();
}

public void Calculate() {

n1 = int.Parse(number1.text);
n2 = int.Parse(number2.text);
result = n1 + n2;
numberLine.value = result;
Text coord = Instantiate(coordinate, coordinate.transform.position, Quaternion.identity) as Text;
coord.transform.parent = c.transform;
coord.transform.localScale = new Vector3(1.0f, 1.0f, 1.0f);
coord.text = result.ToString();

}
}
[/script]


So I want to add a 3rd number to be added for the game. When I play the game I can enter the 3rd number on the canvas but when I hit enter it does not calculate at all, instead it goes back the scene screen with this error message?


NullReferenceException: Object reference not set to an instance of an object
NumberLine.Calculate () (at Assets/NumberLine.cs:36) ( I have it in blue below)

[script}]
using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class NumberLine : MonoBehaviour {

public InputField number1;
public InputField number2;
public InputField number3;
public Slider numberLine;
public Text coordinate;
public GameObject spawner;
public Canvas c;

//public Button calc;
private int result = 0;
private int n1 = 0;
private int n2 = 0;
private int n3 = 0;
public Text results;
// Use this for initialization


// Update is called once per frame
void Update () {
result = n1 + n2 + n3;
//string r = result.ToString();
Debug.Log(result.ToString());
results.text = result.ToString();
}

public void Calculate() {

n1 = int.Parse(number1.text);
n2 = int.Parse(number2.text);
n3 = int.Parse(number3.text);
result = n1 + n2 + n3;
numberLine.value = result;
Text coord = Instantiate(coordinate, coordinate.transform.position, Quaternion.identity) as Text;
coord.transform.parent = c.transform;
coord.transform.localScale = new Vector3(1.0f, 1.0f, 1.0f);
coord.text = result.ToString();

}
}
[/script]

Any ideas?

Thanks

 

if the blue line really is line 36, the only option is that number3 is not assigned. if you have it as a public field i'm guessing you assign it in the editor. double check that it's set there.

 

Ah you are both right I did not assign text three in the inspector for my public variable

Thanks!

 

glad you got it sorted out