C#•4w ago

I am attempting to assign an integer value to a 2d array, but I get a null reference error✅

The specific error is "NullReferenceException: Object Reference Not Set To An Instance Of An Object". Here is my code:

28 Replies

41phaNum3r1ca1•4w ago

tileBuildings is a 2 dimensional int array currentlySelectedTile is a Vector2Int variable

41phaNum3r1ca1•4w ago

all references have been assigned

41phaNum3r1ca1•4w ago

I defined it's size here

41phaNum3r1ca1•4w ago

tileCountX and TileCountY I defined in the game editor; they are public variables

Buddy•4w ago

In many places here you can get null reference exception Please code safely Don't just assume the object always exists

41phaNum3r1ca1•4w ago

which object? I am confused

Buddy•4w ago

Please use $paste

MODiX•4w ago

If your code is too long, you can post to https://paste.mod.gg/ and copy the link into chat for others to see your shared code!

Buddy•4w ago

Screenshots are by far worse unless it is important, like showing unity inspector, errors and so forth.

41phaNum3r1ca1•4w ago

https://paste.mod.gg/okhzdwzmtodc/0

BlazeBin - okhzdwzmtodc

A tool for sharing your source code with the world!

Buddy•4w ago

And which line do you get the error? Is it in this code snippet?

    manager.GetComponent<GameManager>().tileBuildings[playerCamera.GetComponent<clickOnTile>().currentlySelectedTile.x, playerCamera.GetComponent<clickOnTile>().currentlySelectedTile.y] = 1;

    manager.GetComponent<GameManager>().tileBuildings[playerCamera.GetComponent<clickOnTile>().currentlySelectedTile.x, playerCamera.GetComponent<clickOnTile>().currentlySelectedTile.y] = 1;

41phaNum3r1ca1•4w ago

yes one moment, my entire game seems to be broken, and I am not sure why

Buddy•4w ago

Your code doesn't seem complete missing class and few variables

41phaNum3r1ca1•4w ago

I have not pasted in anything that is not related to the issue, let me recheck to ensure I have gotten everything important

Buddy•4w ago

Would you mind pasting the entire class?

41phaNum3r1ca1•4w ago

I will

Buddy•4w ago

Either way. Everytime you have a GetComponent you assume it exists, but what happens if it doesn't? Also you can save performance by saving the components into cache and re-use them GetComponent is fairly expensive

41phaNum3r1ca1•4w ago

I know that these components exist, I will look into using the cache

Buddy•4w ago

I suggest using the debugger

41phaNum3r1ca1•4w ago

now I am recieving the error somewhere else and it has completely halted my code, will change the pasted code to that

Buddy•4w ago

Set a breakpoint at that line, attach the debugger run the game in debug mode. Whenever the game will execute said line it will break and you can see the values in your IDE Assuming you use Visual Studio Community 2022 or JetBrains Rider

41phaNum3r1ca1•4w ago

I have updated the pasted code will do

Buddy•4w ago

You must re-paste the link as the link changes when you make changes (and save)

41phaNum3r1ca1•4w ago

https://paste.mod.gg/tzqzlapbhima/0

BlazeBin - tzqzlapbhima

A tool for sharing your source code with the world!

Buddy•4w ago

Okay, so let me show you where the possibilities of a null reference exception in this snippet can be. - GetComponent<GameManager>() can return null - which can lead to a null reference exception - tileBuildings can be null - which can lead to a null reference exception - GetComponent<clickOnTile>() can be null - which can lead to a null reference exception - currentlySelectedTile can be null - which can lead to a null reference exception - manager can be null - which can lead to a null reference exception (But I see you have set it in your inspector) So if any of those fails, it will throw a null reference exception I suggest you split up your code and prefer as I mentioned earlier, save it into cache. Assuming the components never changes transform. You can save them into cache in Awake or Start

private clickOnTile myComponent;
void Start()
{
  myComponent = GetComponent<clickOnTile>();
}

private clickOnTile myComponent;
void Start()
{
  myComponent = GetComponent<clickOnTile>();
}

Also note that your manager is already of type GameManager, so using GetComponent<GameManager>() on a type of already GameManager doesn't make sense

41phaNum3r1ca1•4w ago

oh my god I get now why I couldnt call a variable from a reference earlier see, I made a reference to a gameobject and tried to go gameobject.variable and was confused that I had to gameobject.GetComponent<ScriptName>().variable when for the game manager I could just manager.variable it is because the game manager class is a script, not a type of game object! I have determinded the null value I had forgotten to set a reference in a different script, which was somehow causing a null value here this is solved ✅

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I am attempting to assign an integer value to a 2d array, but I get a null reference error✅