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Subsections

ISSET Test If Variable Set

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
            ans    double                    []
--> isset('a')
ans = 
  <logical>  - size: [1 1]
 0  
--> a = [];
--> isset('a')
ans = 
  <logical>  - size: [1 1]
 0  
--> a = 2;
--> isset('a')
ans = 
  <logical>  - size: [1 1]
 1



Samit K. Basu 2005-03-16