Changing value of readonly array

Question

I have this jagged array in C#:

    private static readonly float[][] Numbers = {
    new float[]{ 0.3f, 0.4f, 0.5}};

How can I override the value?

public static void SetNewNumbers(float[][] num){
    Numbers = num;}

This is not working because of readonly,what should be added? ( I cant change anything about Numbers)

That is the point of readonly, so you can't assign new value to it. — Guru Stron
– Guru Stron, Commented Feb 12, 2021 at 9:56
If num has the same number of outermost elements as Numbers, you're OK (i.e. 1 element, in your example). Otherwise, you're out of luck: that's the point of readonly — canton7
– canton7, Commented Feb 12, 2021 at 9:56
But in case if outer arrays have the same number of inner ones you can just reassign them one by one. — Guru Stron
– Guru Stron, Commented Feb 12, 2021 at 9:57
Thank you for answers. Yes, they are the same, just different float values. I cant change anything about Numbers. What I need is: If a certain criteria is met I want to override this values, but if later the criteria is not met anymore, I want to return to the default values set in Numbers — DD995
– DD995, Commented Feb 12, 2021 at 10:06
It's readonly, therefore you can only assign it when you initialize it or in the constructor. If you want to change the values later, you should not make it readonly. What was the reason you put readonly there to begin with? Edit: You want if certain criteria is met, to go back to the default. In this case, maybe make two variables? One readonly which is the default, and another one which actually holds the current value, which is not readonly? — Rick
– Rick, Commented Feb 12, 2021 at 10:13

JonasH · Accepted Answer · 2021-02-12 10:38:48Z

2

here is the info you need:

In a field declaration, readonly indicates that assignment to the field can only occur as part of the declaration or in a constructor in the same class. A readonly field can be assigned and reassigned multiple times within the field declaration and constructor.

when you declare Numbers read only then this is not allowed

Numbers = num

coz you can not change the reference but you can modify the object...

so this is valid:

Numbers[0] = new[] {0.0f, 0.0f, 0.0f};
Numbers[0][1] = 1.0f;

edited Feb 12, 2021 at 10:38

JonasH

38.5k2 gold badges16 silver badges31 bronze badges

answered Feb 12, 2021 at 10:24

ΦXocę 웃 Пepeúpa ツ

48.4k17 gold badges77 silver badges102 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

NetMage · Accepted Answer · 2021-02-12 21:22:20Z

1

You can reassign each value in Numbers assuming the new array matches:

void ResetNumbers(float[][] num) {
    if (num.Length != Numbers.Length || num[0].Length != Numbers[0].Length)
        throw new ArgumentException($"{nameof(num)} dimensions incorrect");

    for (int j1 = 0; j1 < Numbers.Length; ++j1) {
        for (int j2 = 0; j2 < Numbers[j1].Length; ++j2) {
            Numbers[j1][j2] = num[j1][j2];
        }
    }
}

answered Feb 12, 2021 at 21:22

NetMage

27.1k3 gold badges39 silver badges57 bronze badges

Collectives™ on Stack Overflow

Changing value of readonly array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related