# Simulink - How to create a conditional "if" block with more than 3 conditions?

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Katarina Vuckovic on 18 Sep 2019
Commented: Nachiket Bapat on 23 Feb 2021
Simulink - How do I create a conditional "if" block with more than 3 statements?
For example:
if(a>2)
do something
elseif (b>3)
do something else
elseif (c>4)
do something else
elseif (a<2 and c<2)
do something else
else
do default
end
What have I tried so far:
• The default "if" block permits only 2 conditions + default.
• I tried using the "case" but case only take one input and I need multiple inputs and 1 output (different depending on the conditions).
Nom on 18 Sep 2019
Edited: Nom on 18 Sep 2019
I'm running the script and it seems to be running fine for me.
a = 1;
b = 1;
c = 1;
if(a>2)
disp('first');
elseif (b>3)
disp('second');
elseif (c>4)
disp('third');
elseif (a<2 && c<2)
disp('fourth');
else
disp('default');
end
The issue I think you're facing is once a statement is true (e.g. if b is greater than 3, hence second if statement is correct). The program will exit the if statement and not check if a<2 && c<2.
One way to solve this issue (may not be the best but it should work) is just dividing the if statements into seperate statements instead of creating multiple elseifs.
Katarina Vuckovic on 18 Sep 2019
I used the user defined function and it worked. Thank you David K.
Also, the image is very helpful and now I see how I can do it in the window.

David K. on 18 Sep 2019
When you know the matlab code needed to do something in Simulink a Matlab Fuction Block can be added to solve the problem.
However, the IF block can also do multiple else ifs as shon below.
Nachiket Bapat on 23 Feb 2021
can someone let me know what im doing wrong ?