The third elseif does not work. I cannot figure out what's wrong with my code.

slots_a1 = zeros(10,10);

slots_a2 = zeros(10,10);

slots_a3 = zeros(10,10);

slots_a4 = zeros(10,10);

slots_a5 = zeros(10,10);

slots_b1 = zeros(10,10);

slots_b2 = zeros(10,10);

slots_b3 = zeros(10,10);

slots_b4 = zeros(10,10);

slots_b5 = zeros(10,10);

index_a1 = 1;

index_a2 = 1;

index_a3 = 1;

index_a4 = 1;

index_a5 = 1;

index_b1 = 1;

index_b2 = 1;

index_b3 = 1;

index_b4 = 1;

index_b5 = 1;

sum_a1 = 0;

sum_a2 = 0;

sum_a3 = 0;

sum_a4 = 0;

sum_a5 = 0;

sum_b1 = 0;

sum_b2 = 0;

sum_b3 = 0;

sum_b4 = 0;

sum_b5 = 0;

index_ab11=index_a1+index_a2+index_a3+index_a4+index_a5+index_b1+index_b2+index_b3+index_b4+index_b5;

for c = 10:100

%personal information

name = input ('Enter Name: ', 's');

contactno = input ('Enter Contact Number: ');

address = input ('Enter Complete Address: ', 's');

fprintf(1, '\n');

disp ('Choose your preferred vaccination site');

disp ('1 for Aguinaldo Elementary School');

disp ('2 for Binakayan Hospital and Medical Center');

site = input("Enter 1 or 2: ");

if site < 1 || site > 2

continue

elseif site == 1 && (sum_a1 < 100 || sum_a2 < 100 || sum_a3 < 100 || sum_a4 < 100 || sum_a5 < 100)

disp ('Vaccination site: Aguinaldo Elementary School');

fprintf(1, '\n');

%choose vaccine

disp ('Choose your preferred vaccine');

disp ('Pfizer, AstraZeneca, Sinovac')

vaccine = input ('Enter name of vaccine (ex. AstraZeneca): ', 's');

fprintf(1, '\n');

%choose date

disp ('Choose on the following dates (MMDDYY)')

disp ('Aug0221 Aug0921 Aug1621 Aug2321 Aug3021')

date = input('Enter date of first dose (AugDDYY):', 's');

if date == 'Aug0221'

disp ('Date of first dose: Aug0221')

fprintf(1, '\n');

%assign a slot

slots_a1(index_a1)=1;

sum_a1=sum_a1+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_a1)]);

fprintf(1, '\n');

%represent slot chart

slot_charta1=slots_a1

index_a1=index_a1+1;

end

if date == 'Aug0921'

disp ('Date of first dose: Aug0921')

fprintf(1, '\n');

%assign a slot

slots_a2(index_a2)=1;

sum_a2=sum_a2+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_a2)]);

fprintf(1, '\n');

%represent slot chart

slot_charta2=slots_a2

index_a2=index_a2+1;

end

if date == 'Aug1621'

disp ('Date of first dose: Aug1621')

fprintf(1, '\n');

%assign a slot

slots_a3(index_a3)=1;

sum_a3=sum_a3+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_a3)]);

fprintf(1, '\n');

%represent slot chart

slot_charta3=slots_a3

index_a3=index_a3+1;

end

if date == 'Aug2321'

disp ('Date of first dose: Aug2321')

fprintf(1, '\n');

%assign a slot

slots_a4(index_a4)=1;

sum_a4=sum_a4+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_a4)]);

fprintf(1, '\n');

%represent slot chart

slot_charta4=slots_a4

index_a4=index_a4+1;

end

if date == 'Aug3021'

disp ('Date of first dose: Aug3021')

fprintf(1, '\n');

%assign a slot

slots_a5(index_a5)=1;

sum_a5=sum_a5+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_a5)]);

fprintf(1, '\n');

%represent slot chart

slot_charta5=slots_a5

index_a5=index_a5+1;

end

elseif site == 2 && (sum_b1 < 100 || sum_b2 < 100 || sum_b3 < 100 || sum_b4 < 100 || sum_b5 < 100)

disp ('Vaccination site: Binakayan Hospital and Medical Center');

fprintf(1, '\n');

%choose vaccine

disp ('Choose your preferred vaccine');

disp ('Pfizer, AstraZeneca, Sinovac')

vaccine = input ('Enter name of vaccine (ex. AstraZeneca): ', 's');

fprintf(1, '\n');

%choose date

disp ('Choose on the following dates (MMDDYY)')

disp ('Aug0321 Aug1021 Aug1721 Aug2421 Aug3121')

date = input('Enter date of first dose (AugDDYY):', 's');

if date == 'Aug0321'

disp ('Date of first dose: Aug0321')

fprintf(1, '\n');

%assign a slot

slots_b1(index_b1)=1;

sum_b1=sum_b1+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Binakayan Hospital and Medical Center');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_b1)]);

fprintf(1, '\n');

%represent slot chart

slot_chartb1=slots_b1

index_b1=index_b1+1;

end

if date == 'Aug1021'

disp ('Date of first dose: Aug1021')

fprintf(1, '\n');

%assign a slot

slots_b2(index_b2)=1;

sum_b2=sum_b2+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Binakayan Hospital and Medical Center');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_b2)]);

fprintf(1, '\n');

%represent slot chart

slot_chartb2=slots_b2

index_b2=index_b2+1;

end

if date == 'Aug1721'

disp ('Date of first dose: Aug1721')

fprintf(1, '\n');

%assign a slot

slots_b3(index_b3)=1;

sum_b3=sum_b3+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Binakayan Hospital and Medical Center');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_b3)]);

fprintf(1, '\n');

%represent slot chart

slot_chartb3=slots_b3

index_b3=index_b3+1;

end

if date == 'Aug2421'

disp ('Date of first dose: Aug2421')

fprintf(1, '\n');

%assign a slot

slots_b4(index_b4)=1;

sum_b4=sum_b4+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Binakayan Hospital and Medical Center');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_b4)]);

fprintf(1, '\n');

%represent slot chart

slot_chartb4=slots_b4

index_b4=index_b4+1;

end

if date == 'Aug3121'

disp ('Date of first dose: Aug3121')

fprintf(1, '\n');

%assign a slot

slots_b5(index_b5)=1;

sum_b5=sum_b5+1;

%print reservation

disp ('COVID-19 Vaccine Reservation')

fprintf ('Name: %s\n', name);

fprintf ('Contact Number: %.f\n', contactno);

fprintf ('Address: %s\n', address);

disp('Vaccination Site: Aguinaldo Elementary School');

fprintf('Date of Vaccination: %s\n', date');

fprintf('Preferred Vaccine: %s\n', vaccine');

disp ('Note: If the preferred vaccine are not available, the vaccine that is available will be administered');

disp(['Slot number: ', num2str(index_b5)]);

fprintf(1, '\n');

%represent slot chart

slot_chartb5=slots_b5

index_b5=index_b5+1;

end

elseif (site == 1 && (sum_a1 >= 100 || sum_a2 >= 100 || sum_a3 >= 100 || sum_a4 >= 100 || sum_a5 >= 100)) || (site == 2 && (sum_b1 >= 100 || sum_b2 >= 100 || sum_b3 >= 100 || sum_b4 >= 100 || sum_b5 >= 100))

disp('Sorry, your preferred date of vaccination is already full. Kindly choose another date that is available for you.')

end

end

[Torsten]

The ||'s in the sum parts of the third elseif statement must be replaced by &'s.

[Jan]

Avoid hidden indices in the names of variablöes. Use arrays instead.

Compare:

slots_a1 = zeros(10,10);
slots_a2 = zeros(10,10);
slots_a3 = zeros(10,10);
slots_a4 = zeros(10,10);
slots_a5 = zeros(10,10);

with:

slots_a = zeros(5, 10, 10);

and

index_ab11=index_a1+index_a2+index_a3+index_a4+index_a5+index_b1+index_b2+index_b3+index_b4+index_b5;

with

index_ab11 = sum(index_a) + sum(index_b);

Answer 1

[Steven Lord]

slots_a1 = zeros(10,10);
slots_a2 = zeros(10,10);
slots_a3 = zeros(10,10);
slots_a4 = zeros(10,10);
slots_a5 = zeros(10,10);
slots_b1 = zeros(10,10);
slots_b2 = zeros(10,10);
slots_b3 = zeros(10,10);
slots_b4 = zeros(10,10);
slots_b5 = zeros(10,10);

Naming variables this way is an anti-pattern. Rather than defining variables with numbers in their names, define them as arrays.

slots_a = zeros(10, 10, 5);

Now rather than duplicating code to refer to slots_a1, slots_a2, etc. you can loop over the third dimension and access slots_a(:, :, 1), etc. Similarly you can now use functions like sum with a dimension input.

A = cat(3, magic(4), randi(10, 4, 4), eye(4))

A = 
A(:,:,1) =

    16     2     3    13
     5    11    10     8
     9     7     6    12
     4    14    15     1


A(:,:,2) =

     9     9     1     4
     6     2     9     5
     5     1     2    10
    10     7     7     2


A(:,:,3) =

     1     0     0     0
     0     1     0     0
     0     0     1     0
     0     0     0     1

sum(A, 3)

ans = 4×4

26 11 4 17 11 14 19 13 14 8 9 22 14 21 22 4

sum(A, 1) % Sum down the columns of each page of A

ans = 
ans(:,:,1) =

    34    34    34    34


ans(:,:,2) =

    30    19    19    21


ans(:,:,3) =

     1     1     1     1

Doing this may help you avoid or reduce code duplication.