has

Check if ROS parameter name exists

Since R2019b

Syntax

exists = has(ptree,paramname)

Description

exists = has(ptree,paramname) checks if the parameter with name paramname exists in the parameter tree, ptree.

Examples

Check If ROS Parameter Exists

Connect to a ROS network. Create a parameter tree and check for the 'MyParam' parameter.

rosinit

Launching ROS Core...
Done in 0.38608 seconds.
Initializing ROS master on http://172.29.205.71:54865.
Initializing global node /matlab_global_node_24971 with NodeURI http://dcc066343glnxa64:40363/ and MasterURI http://localhost:54865.

ptree = rosparam;
has(ptree,'MyParam')

ans = logical
   0

Set the 'MyParam' parameter and verify it exists. Disconnect from ROS network.

set(ptree,'MyParam','test')
has(ptree,'MyParam')

ans = logical
   1

rosshutdown

Shutting down global node /matlab_global_node_24971 with NodeURI http://dcc066343glnxa64:40363/ and MasterURI http://localhost:54865.
Shutting down ROS master on http://172.29.205.71:54865.

Input Arguments

ptree — Parameter tree

ParameterTree object handle

Parameter tree, specified as a ParameterTree object handle. Create this object using the rosparam function.

paramname — ROS parameter name

string scalar | character vector

ROS parameter name, specified as a string scalar or character vector. This string must match the parameter name exactly.

Output Arguments

exists — Flag indicating whether the parameter exists

true | false

Flag indicating whether the parameter exists, returned as true or false.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2019b