Editing Foreach loop (section)

{{Short description|Control flow statement for traversing items in a collection}}
{{for|"for all" in logic (∀)|Universal quantification}}
[[File:For-Loop-Mint-Programming-Language-Type-2.gif|thumb|{{mono|foreach}} loops are almost always used to iterate over items in a sequence of elements.]]
{{Loop constructs}}<!-- DO NOT remove. Discuss navigation concept at [[Talk:Do while loop#Helpbox experiment]] -->

In [[computer programming]], '''foreach loop''' (or '''for-each loop''') is a [[control flow]] statement for traversing items in a [[Collection class|collection]]. {{mono|foreach}} is usually used in place of a standard {{mono|[[For loop|for]]}} loop [[Statement (computer science)|statement]]. Unlike other {{mono|for}} loop constructs, however, {{mono|foreach}} loops<ref>{{cite web
| url=http://www.digitalmars.com/d/statement.html#ForeachStatement
| title=D Programming Language <code>foreach</code> Statement Documentation
| access-date=2008-08-04
| publisher=Digital Mars
}}</ref> usually maintain no explicit counter: they essentially say "do this to everything in this set", rather than "do this {{mono|x}} times". This avoids potential [[off-by-one error]]s and makes code simpler to read. In [[object-oriented]] languages, an [[iterator]], even if implicit, is often used as the means of traversal.

The {{mono|foreach}} statement in some languages has some defined order, processing each item in the collection from the first to the last.
The {{mono|foreach}} statement in many other languages, especially [[array programming]] languages, does not have any particular order. This simplifies [[loop optimization]] in general and in particular allows [[vector processing]] of items in the collection concurrently.