How to programatically select a item in list using c#?

How do I replace an item on a list using Scheme?

• For example, if my list contains apples oranges and bananas, how do I replace bananas with pineapples?

• Answer:

  Generally you don't replace the item(s) in an existing list. Instead you process the old list and build a new list that contains the modifications you want. Something like this: (define replace-string-in-list (lambda (ls old new)     (cond         ( (null? ls) '() )         ( (string=? (car ls) old) (cons new (replace-string-in-list (cdr ls) old new )) )         ( else (cons (car ls) (replace-string-in-list (cdr ls) old new )) )))) If you really must replace items in place in an existing list then you can walk the list and use the set-car! procedure (or its equivalent in your dialect of Scheme) to replace the old value with the desired new value whenever you encounter it.