Loops/Foreach: Difference between revisions

=={{header|Ada}}==

===arrays===

use Ada.Integer_Text_IO;

 

end loop;

 

 

===doubly linked lists===

{{works with|Ada 2005}}

use Ada.Integer_Text_IO, Ada.Containers;

 

DL_List.Iterate (Print_Node'Access);

 

===vectors===

{{works with|Ada 2005}}

use Ada.Integer_Text_IO, Ada.Containers;

 

V.Iterate (Print_Element'Access);

 

=={{header|ALGOL 68}}==

{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}}

{{works with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386}}

 

FOR index FROM LWB collection TO UPB collection DO

print((collection[index]," "))

Output:

Note: [[ALGOL 68S]] actually has a reserved word FOREACH that is used to

break arrays in to portions, and process in parallel.

ENDPROC</lang>

=={{header|AutoHotkey}}==

Loop, Parse, string, `,

 

=={{header|AWK}}==

=={{header|C++}}==

C++ does not (yet) have a "for each" loop. The following is a generic loop which works with any standard container except for built-in arrays. The code snippet below assumes that the container type in question is typedef'd to <tt>container_type</tt> and the actual container object is named container.

However the idiomatic way to output a container would be

There's also an algorithm named <tt>for_each</tt>. However, you need a function or function object to use it, e.g.

{

std::cout << v << "\n";

 

...

 

The next version of the standard will allow the following simplified syntax:

 

for (auto element: container)

{

std::cout << element << "\n";

Here <tt>container</tt> is the container variable, <tt>element</tt> is the loop variable (initialized with each container element in turn), and auto means that the compiler should determine the correct type of that variable automatically. If the type is expensive to copy, a const reference can be used instead:

 

for (auto const& element: container)

{

std::cout << element << "\n";

Of course the container elements can also be changed by using a non-const reference (provided the container isn't itself constant).

 

 

=={{header|Common Lisp}}==

or

 

=={{header|D}}==

 

=={{header|Forth}}==

 

=={{header|F_Sharp|F#}}==

We can use ''for'' directly or list iteration.

 

 

=={{header|HaXe}}==

 

=={{header|Haskell}}==

which is the same as

 

=={{header|J}}==

 

=={{header|Lisaac}}==

word.print;

'\n'.print;

 

=={{header|Logo}}==

=={{header|MAXScript}}==

(

print i

 

=={{header|Metafont}}==

 

=={{header|Io}}==

 

=={{header|MOO}}==

for v = b

disp(v); % v is the column vector [1;5], then [2;6] ...

 

We can also iterate over structures:

{{works with|Rakudo|#21 "Seattle"}}

 

say $i;

}</lang>

=={{header|Pop11}}==

Iteration over list:

for el in lst do

printf(el,'%p\n');

=={{header|PowerShell}}==

<lang powershell>foreach ($x in $collection) {

For example:

 

f = open('somefile','r')

for eachline in f:

chracters += 1

 

 

=={{header|R}}==

=={{header|TI-89 BASIC}}==

 

Define strs = {"Lorem","ipsum","dolor"}

For i, 1, dim(strs)

Disp strs[i]

 

=={{header|UNIX Shell}}==

 

=={{header|V}}==

 

=={{header|VBScript}}==

 

=={{header|Visual Basic .NET}}==

 

 

=={{header|XSLT}}==

For-each is the only iteration construct that is built into XSLT. All other iteration is either implied by applying a template to all members matching an XPath expression, or built from recursive application of a template. You have access to something like a loop counter with the one-based "position()" function.

</xsl:for-each>