if elseif else statement not working

Hello, I have just gotten back into matlab and I am practicing the else if statememts. this is currently what I am running:

function [L,w,o] = SortLargestNumber(input,input1,input2)

x = input;

c = input1;

m = input2

x

c

m

HighestNumber = 0;

if x>c && m

HighestNumber = x;

elseif c>x && m

HighestNumber = c;

else m>x && c

HighestNumber = m;

end

HighestNumber

end

I am not sure what I am doing wrong with the else if statement as I am only trying to sort which number is highest. can someone point out why and perhaps provide a better example of doing this? I know the variables are bad, its practice.

Thanks!

-Kie

[Image Analyst]

What are L, w, and o? You need to define the. o is a bad name by the way.

Answer 1

[Dave B]

You're writing "x is greater than c and m" and probably thinking of this as "x is greater than c, and x is greater than m". But MATLAB doesn't think of it this way, it sees "x is greater than c...and, unrelated, m" (it interprets that as m>0):

SortLargestNumber(10, 9, 8)

m = 8

x = 10

c = 9

m = 8

HighestNumber = 10

SortLargestNumber(1, 9, 8)

m = 8

x = 1

c = 9

m = 8

HighestNumber = 9

SortLargestNumber(1, 9, 80)

m = 80

x = 1

c = 9

m = 80

ans = logical
   1

HighestNumber = 80

function [L,w,o] = SortLargestNumber(input,input1,input2)
x = input;
c = input1;
m = input2
x
c
m
HighestNumber = 0;
    if x>c && x>m
        HighestNumber = x;
    elseif c>x && c>m
        HighestNumber = c;   
    elseif m>x && m>c
        HighestNumber = m;
    end
    
    HighestNumber
   
end

[Kieran Smith]

Ohhhhhh, was the problem solely needing to edit the if statements to be "x>c && xm" etc? That's a good point if so, that did not cross my mind for some reason.

[Dave B]

Yes, think of each thing between && and || as being totally independent. Also if your goal is to find the largest number, I fully agree with - just use max, but if your goal is to learn how to write a function that finds the largest number, some more feedback:

• what about the cases where there are ties?
• how would you extend this to 4 arguments?...the code will have to grow quite a bit with each additional value
• Consider setting the initial value of HighestNumber to NaN, it might make it easier to notice an error.
• What are the outputs of this function supposed to be?

Answer 2

[David Hill]

If-Else Method:

function largestNumber = SortLargestNumber(x,c,m)
    if x>=c && x>=m
        largestNumber = x;
    elseif c>x && c>=m
        largestNumber = c;
    else
        largestNumber = m;
end

Better method with built-in function:

largestNumber = max([x,c,m])

[Kieran Smith]

Wow, that is way more efficient! thankyou for the insight!