exist

Determine whether variable exists in connected data source

Since R2024a

Syntax

varExists = exist(connectionObj,varNames)

Description

varExists = exist(connectionObj,varNames) returns 1 (true) if the specified variables varNames exist in the connected data source connectionObj, and 0 (false) otherwise. If varNames is an array, the output varExists is an array of the same size as varNames, and varExists(i) indicates whether the variable name varNames(i) exists in the connected data source.

If a data connection can access multiple data sources (for example, a data dictionary and its referenced dictionaries), the function returns 1 (true) if the variable exists in any of the visible data sources.

Examples

Check for Specified Variable in MAT file

matFile = Simulink.data.connect("myMatFile.mat");
exist(matFile,"a")

ans = 

logical
    1

Check for Specified Variables in Data Dictionary

dd = Simulink.data.connect("myDictionary.sldd");
dd.a = 1;
dd.c = 3;
exist(dd,["a" "b" "c"])

ans = 

  1×3 logical array

   1   0   1

Input Arguments

connectionObj — Connection to data source

Simulink.data.DataConnection object

Connection to data source, specified as a Simulink.data.DataConnection object.

varNames — Variable names

string | character vector | string array | cell array of character vectors

Variable names, specified by a string, character vector, string array, or cell array of character vectors.

Version History

Introduced in R2024a