foreach record update record field with index

If you're looping through records using a foreach, you can use an index to update field3 like this:

int index = 0;  
foreach (var record in records)  
{  
    record.field3 = index;  
    index++;  
}

This way, field3 will hold the index value for each record. 

If you're looping through records using a foreach, you can use an index to update field3 like this:

int index = 0;  
foreach (var record in records)  
{  
    record.field3 = index;  
    index++;  
}

This way, field3 will hold the index value for each record.