Thread Safety of static Array used as lookup table

  • Thread starter Thread starter Mark M
  • Start date Start date
M

Mark M

Hi all,

Is the follow construct thread safe to access via indexer?

public static readonly string [] GradeLookupTable = new string[]
{
"*","PK","K","1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","HS","UG"
};

Usage:

string grade = GradeLookupTable[12];

Thanks for your help!
 
Is the follow construct thread safe to access via indexer?
Yes

But you should know that setting the field as readonly doesnt mean that
the values of the array cannot be altered. The following code will
change the value of the element at index 2:

GrageLookupTable[2] = "Test";

To make it truly readonly, make the field a property and return a clone
of the array so that no one can change the original values of the
array:

public static Grades {
get {return GradeLookupTable.Clone() as string[];}
}

- NuTcAsE
 
NuTcAsE said:
Is the follow construct thread safe to access via indexer?
Click to expand...
Yes

But you should know that setting the field as readonly doesnt mean that
the values of the array cannot be altered. The following code will
change the value of the element at index 2:

GrageLookupTable[2] = "Test";

To make it truly readonly, make the field a property and return a clone
of the array so that no one can change the original values of the
array:

public static Grades {
get {return GradeLookupTable.Clone() as string[];}
}
Click to expand...

Or preferrably provide a property which provides a read-only view on
the array - you don't really want to create a new copy of the array
every time you access the property.
 
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