# persistent

Declares a list of variables as persistent. When a variable is declared as persistent, its value is retained after the function exits.

persistent x

## Inputs

x
A variable name to be declared as persistent.
Type: string
Dimension: string

## Example

function b=foo()
persistent z;

if (isempty(z))
z=1;
else
z=z+1;
end
b=z;
end

foo
foo
ans =1
ans = 2