Use of const in a method

Question

In the following method,

public void InspectList(IList<int> values)
{
    if(values != null)
    {
        const string format = "Element At {0}";
        foreach(int i in values)
        {
            Log(string.Format(format, i));
        }
    }   
}

Does the use of const provide any benefit over just declaring the string as a string? Woudl it not be interned anyway?

Answer 1

True, in both cases it will be interned.

Marking it as a const makes your meaning clearer - do not touch this string variable, do not assign a different value to it.

Answer 2

Here's how your final code will look like in the two cases:

• Using const:

  public void InspectList(IList<int> values)
  {
      if(values != null)
      {
          foreach(int i in values)
          {
              Log(string.Format("Element At {0}", i));
          }
      }   
  }
  

• Without const:

  public void InspectList(IList<int> values)
  {
      if(values != null)
      {
          string format = "Element At {0}";
          foreach(int i in values)
          {
              Log(string.Format(format, i));
          }
      }   
  }
  

So in the second case you will have an additional local variable declared, but IMHO the difference would be microscopic.