Variable length arrays in C#

Question

I have a class which defines few global variables as below: ``` namespace Algo { public static class AlgorithmParameters { public int pop_size = 100; } } ``` In my another csharp file, which also contains the main(), and in the main() I am declaring an array of type structure and the array size as pop_size but I am getting some error on `"chromo_typ Population[AlgorithmParameters.pop_size];"`. Please find the code below. Am I using a incorrect syntax for array declaration of variable length size?? ``` namespace Algo { class Program { struct chromo_typ { string bits; float fitness; chromo_typ() { bits = ""; fitness = 0.0f; } chromo_typ(string bts, float ftns) { bits = bts; fitness = ftns; } }; static void Main(string[] args) { while (true) { chromo_typ Population[AlgorithmParameters.pop_size]; } } } } ``` Error is: ``` Bad array declarator: To declare a managed array the rank specifier precedes the variable's identifier. To declare a fixed size buffer field, use the fixed keyword befor…

Accepted Answer

You don't specify the size when you declare the variable, you specify it when you create the instance of the array:

```
chromo_typ[] Population = new chromo_typ[AlgorithmParameters.pop_size];
```

Or if you separate the declaration and creation:

```
chromo_typ[] Population;
Population = new chromo_typ[AlgorithmParameters.pop_size];
```

Variable length arrays in C#

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