Ignore Function Outputs

This example shows how to ignore specific outputs from a function using the tilde (~) operator.

Request all three possible outputs from the fileparts function.

helpFile = which('help');
[helpPath,name,ext] = fileparts(helpFile);

The current workspace now contains three variables from fileparts: helpPath, name, and ext. In this case, the variables are small. However, some functions return results that use much more memory. If you do not need those variables, they waste space on your system.

If you do not use the tilde operator, you can request only the first $N$ outputs of a function (where $N$ is less than or equal to the number of possible outputs) and ignore any remaining outputs. For example, request only the first output, ignoring the second and third.

helpPath = fileparts(helpFile);

If you request more than one output, enclose the variable names in square brackets, []. The following code ignores the output argument ext.

[helpPath,name] = fileparts(helpFile);

To ignore function outputs in any position in the argument list, use the tilde operator. For example, ignore the first output using a tilde.

[~,name,ext] = fileparts(helpFile);

You can ignore any number of function outputs using the tilde operator. Separate consecutive tildes with a comma. For example, this code ignores the first two output arguments.

[~,~,ext] = fileparts(helpFile);

Ignore Function Outputs

Related Topics