how to check whether the variable is present or not ?

hi, I have tried if condition with the help of "exist" as:

 checkVariable1= exist('lbl_edge','var');
if checkVariable1==1
    edge= newedge1;
else
    edge = newedge2;
end

I have also tried

 if any(strcmp(who,'lbl_edge'))==1
....
else
...
end

But none of them are working. Can you please help me...

Thanks

Answer 1

[Mohammad Abouali]

Works on mine. Try this code.

clear;clc;close all
checkVariable1= exist('lbl_edge','var');
if checkVariable1==1
    disp('Exist')
else
    disp('didn''t exist')
end

disp('now creating the variable.')
lbl_edge='something';

checkVariable1= exist('lbl_edge','var');
if checkVariable1==1
    disp('Exist')
else
    disp('didn''t exist')
end

Gives this output

didn't exist
now creating the variable.
Exist

Answer 2

[Image Analyst]

checkVariable1= exist('lbl_edge','var');

will work. Perhaps you have the Image Processing Toolbox and have conflict between your variable name of edge and the IPT function called edge(). Pick a different name.