The following table lists the instruction's hexadecimal and Microsoft Intermediate Language (MSIL) assembly format, along with a brief reference summary:

A2	stelem.ref	Replaces an array element at the supplied index with the ref value (type O) on the stack.

The stack transitional behavior, in sequential order, is:

[The 'ordered' type of list has not been implemented in the ECMA stylesheet.]

The stelem.ref instruction replaces the value of the element at the supplied index in the one-dimensional array array with the ref (type O) value pushed onto the stack.

Arrays are objects and hence represented by a value of type O. The index is type native int.

Note that stelem.ref implicitly casts the supplied value to the element type of array before assigning the value to the array element. This cast can fail, even for verified code. Thus the stelem.ref instruction can throw InvalidCastException. For one-dimensional arrays that aren't zero-based and for multidimensional arrays, the Array class provides a Array.SetValue(object, int) method.

NullReferenceException is thrown if array is a null reference.

IndexOutOfRangeException is thrown if index is negative, or larger than the bound of array.

ArrayTypeMismatchException is thrown if array does not hold elements of the required type.

The following ILGenerator.Emit(OpCode) method overload can use the stelem.ref opcode:

• ILGenerator.Emit(OpCode)

Namespace: System.Reflection.Emit
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0