## ISSET Test If Variable Set

Section: Inspection Functions

### Usage

Tests for the existence and non-emptiness of a variable. the general syntax for its use is

       y = isset('name')

where `name` is the name of the variable to test. This is functionally equivalent to

       y = exist('name','var') & ~isempty(name)

It returns a `logical` 1 if the variable is defined in the current workspace, and is not empty, and returns a 0 otherwise.

### Example

Some simple examples of using `isset`

    --> who
      Variable Name      Type   Flags             Size
                  a    double                    [23 12 5]
                ans    uint32                    [1 1]
                  c     int32                    [1 3]
                  f    string                    [1 5]
                  p    double                    [1 256]
                  x      cell                    [2 1]
                  y    struct                    [1 1]
    --> isset('a')
    ans =
      <logical>  - size: [1 1]
     1
    --> a = [];
    --> isset('a')
    ans =
      <logical>  - size: [1 1]
     0
    --> a = 2;
    --> isset('a')
    ans =
      <logical>  - size: [1 1]
     1