Cannot assign to 's' because it is a 'foreach iteration variable'

[bg_ie]

Hi,

What is wrong with the following -

short[] arrfile = new short[100];

foreach (short s in arrfile)
{
s = 10;
}

Error 1 Cannot assign to 's' because it is a 'foreach iteration
variable'

Thanks,

Barry.

 

[Marc Gravell]

Exactly what it says.

The language does not allow you to reassign a "foreach" variable. Even
if you could, it wouldn't update the contents of hte array. What do
you want to do here? If you want to change the values in the array,
then you will have to do somehing like:

for(int i = 0 ; i < arrfile.Length; i++) {
arrfile = 10;
}

Marc

 

[Hakan Fatih YILDIRIM]

Good point Marc.. Thanks

 

[Moty Michaely]

Good point Marc.. Thanks

Hi,

from MSDN:
"This error occurs when an assignment to variable occurs in a read-
only context. Read-only contexts include foreach iteration variables,
using variables, and fixed variables. To resolve this error, avoid
assignments to a statement variable in using blocks, foreach
statements, and fixed statements."

The foreach keyword just enumerates IEnumerable instances (getting an
IEnumerator instances by calling the GetEnumerator() method).
IEnumerator is read-only, therefore values can't be changed using
IEnumerator => can't be changed using the foreach context.

Hope this helps.
Moty

 

[Aneesh P]

Hi,

from MSDN:
"This error occurs when an assignment to variable occurs in a read-
only context. Read-only contexts include foreach iteration variables,
using variables, and fixed variables. To resolve this error, avoid
assignments to a statement variable in using blocks, foreach
statements, and fixed statements."

The foreach keyword just enumerates IEnumerable instances (getting an
IEnumerator instances by calling the GetEnumerator() method).
IEnumerator is read-only, therefore values can't be changed using
IEnumerator => can't be changed using the foreach context.

Hope this helps.
Moty

This is the IEnumerator problem I've faced. I guess this is a typical
case where we need to go for 'for' loop instead of 'foreach'.