c# - Does using a LINQ statement in a foreach re-evaluate the statement on each iteration -

so wondering whether using linq where clause in foreach loop means on each iteration re-evaluate linq where clause. example:

var myid = 1; foreach (var thing in listofthings.where(x => x.id == myid)) {    //do } 

or better write:

var myid = 1;  var mylist = listofthings.where(x => x.id == myid); foreach (var thing in mylist) {    //do } 

or both work in same way?

this sample should give answers seek:

code

using system; using system.linq;  public class test {     public static void main()     {         // create sequence of integers 0 10         var sequence = enumerable.range(0, 10).where(p =>          {              // in each 'where' clause, print current item.             // shows when clause executed             console.writeline(p);               // make sure every value selected             return true;         });          foreach(var item in sequence)         {             // print marker show when loop body executing.             // helps see if 'where' clauses evaluated              // before loop starts or during loop             console.writeline("loop body exectuting.");         }     } } 

output

0 loop body exectuting. 1 loop body exectuting. 2 loop body exectuting. 3 loop body exectuting. 4 loop body exectuting. 5 loop body exectuting. 6 loop body exectuting. 7 loop body exectuting. 8 loop body exectuting. 9 loop body exectuting. 

conclusion

the where clause evaluated once, current element, @ start of each loop iteration.