length

Determine length of message queue

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Syntax

length(message_name)

Description

example

length(message_name) checks the number of messages in the internal receiving queue of an input or local message.

Examples

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Check Queue Length in State Action

Check the queue for message M. If a message is present, remove it from the queue. If exactly seven messages remain in the queue, increment the value of x.

during:
   if receive(M) == true
      if length(M) == 7
         x = x+1;
      end
   end

Stateflow chart that uses the length operator.

Tips

The length operator is not supported for input messages that use external receiving queues. To use the length operator, enable the Use Internal Queue property for this message.

Version History

Introduced in R2015b