How to create const string from string variable

Question

I want to create const string from another string variable. For example the next two code snippets can't compile

1)

string str = "111";
const string str2 = str;

2)

string str = "111";
const string str2 = new string(str.ToCharArray());

Which results in

Error: The expression being assigned to 'str2' must be constant

Is there any way to create a const string from string variable ?

Constant variable has to be fully known during the compilation, so it's not possible. — MarcinJuraszek
– MarcinJuraszek, Commented Dec 13, 2012 at 14:16

Oded · Accepted Answer · 2012-12-13 14:16:41Z

8

In short - no.

The value assigned to a const must be a compile time constant.

You can use readonly instead of const, which will let you change the value of the variable - you will only be able to change the reference in the constructor.

answered Dec 13, 2012 at 14:16

Oded

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Comments

Soner Gönül · Accepted Answer · 2012-12-13 14:18:18Z

2

Nope. Because const variables are works on compile time.

Everybody agree on using readonly;

readonly string t = s + " World";

answered Dec 13, 2012 at 14:18

Soner Gönül

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Comments

Lloyd · Accepted Answer · 2012-12-13 14:18:50Z

2

Constants are evaluated at compile time so what you want is not possible. However you can substitute the constants with readonly, for example:

string s = "Hello";
readonly string t = s + " World";

answered Dec 13, 2012 at 14:18

Lloyd

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Konrad Viltersten · Accepted Answer · 2012-12-13 14:37:51Z

2

Use readonly keyword.

string str = "111";
readonly string str2 = str.ToCharArray();

edited Dec 13, 2012 at 14:37

Konrad Viltersten

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answered Dec 13, 2012 at 14:17

Roman Melnyk

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