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h2. Loop
The Loop allows to process the a message a number of times and possibly process them in a different way.  Useful mostly for testing.

{info:title=Default mode}
Notice by default the loop uses the same exchange throughout the looping. So the result from the previous iteration is used for the next (eg [Pipes And Filters]). From *Camel 2.8* onwards you can enable copy mode instead. See the options table for more details.
{info}

h3. Options
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|| Name || Default Value || Description ||
| {{copy}} | {{false}} | *Camel 2.8:* Whether or not copy mode is used. If {{false}} then the same Exchange is being used throughout the looping. So the result from the previous iteration will be _visible_ for the next iteration. Instead you can enable copy mode, and then each iteration is _restarting_ with a fresh copy of the input [Exchange]. |

h3. Exchange properties
For each iteration two properties are set on the {{Exchange}} that could be used by processors down the pipeline to process the [Message] in different ways.
|| Property || Description ||
| {{CamelIterationCount}} | Camel 1.x: Total number of iterations to be run |
| {{CamelIterationIndex}} | Camel 1.x: Index of the current iteration (0 based) |
| {{CamelLoopSize}} | Camel 2.0: Total number of loops |
| {{CamelLoopIndex}} | Camel 2.0: Index of the current iteration (0 based) |
that could be used by processors down the pipeline to process the [Message] in different ways.

h4. Examples

The following example shows how to take a request from the *direct:x* endpoint , then send the message repetitively to *mock:result*.  The number of times the message is sent is either passed as an argument to {{loop()}}, or determined at runtime by evaluating an expression.  The expression *must* evaluate to an {{int}}, otherwise a {{RuntimeCamelException}} is thrown.

*Using the [Fluent Builders]*

Pass loop count as an argument