Check existence of variable, script, function, folder, or class
exist name searchType
A = exist(___)
exist returns the type of
name as a number. This list describes the type associated
with each value:
name does not exist or cannot be found
for other reasons. For example, if
name exists in a
restricted folder to which MATLAB® does not have access,
name is a variable in the
name is a file with extension
name is the name of
a file with a non-registered file extension (
name is a MEX-file on your MATLAB search path.
name is a loaded Simulink® model or a Simulink model or library file on
your MATLAB search path.
name is a built-in MATLAB function. This does not include classes.
name is a P-code file on your
MATLAB search path.
name is a folder.
name is a class.
exist returns 0 for Java classes if you start
MATLAB with the
MATLAB searches starting at the top of the search path, and moving down until
a result is found or the last folder on the path is reached. If more than one
name exists in a folder, MATLAB displays the first instance of
name, according to
the Function Precedence Order. Folders
are an exception to the function precedence rules. They have precedence over all
types except for variables and built-in functions.
For example, if
name matches both a file
.m extension and a P-code file, then
6, identifying it as a P-code file. If
both a variable and a P-code file, exists returns 1, identifying it
as a variable. If
name matches both a folder and
a MATLAB function,
identifying it as a folder.
Create a variable named
testresults, and then confirm its existence in the workspace.
testresults = magic(5); exist testresults
ans = 1
A variable named
testresults exists in the workspace.
Create the folder
myfolder, and then check its existence as a folder.
mkdir myfolder; exist myfolder dir
ans = 7
If you specify the type as
file, MATLAB® searches for both files and folders, therefore returning the same result.
exist myfolder file
ans = 7
Check whether the
plot function is a built-in function or a file.
A = exist('plot')
A = 5
This indicates that
plot is a built-in MATLAB function.
name— name of variable, script, function, folder, or class
Name of variable, script, function, folder, or class, specified as a character vector or string scalar.
name can include a partial path, but must be one of
A folder on the search path
In a folder on the search path
The current folder
In the current folder
Subfolders of folders on the path are not searched.
name must include a full path.
name specifies a file with a non-registered
file extension (
include the extension. You can also include an extension to prevent
conflict with other similar file names. For example,
MATLAB does not examine the contents or internal structure of a file and relies solely on the file extension for classification.
searchType— Type of results to search for
Type of results to search for, specified as one of these values:
|searchType||Description||Possible Return Values|
Checks only for built-in functions.
Checks only for classes.
Checks only for folders.
Checks only for files or folders.
2, 3, 4, 6, 7, 0
Checks only for variables.
To check the existence of a file or folder, you also can use the
exist searches for files
and folders on the search path, which can lead to unexpected results.
isfile search for files or folders only on the specified path or
in the current folder, which can lead to clearer and faster results.