comparing strings in alphabetical order

I'm trying to see the which of the input of 2strings(x1,x2) come first alphabetically.(e.g if x1 comes first it will return 1, if x2 comes first it will return -1..)

they need to be in a same length otherwise it doesn't work which is why I did 'MaxLength'.Also I got rid of the blanks in between if it's a sentence.

but I'm trying to compare the ASCII code of each string (a=97) and see which one comes first.

i did this so far but it just won't work.

x1= lower(input('Enter a string: ','s'));
x2= lower(input('Enter a string: ','s'));
x1 = strrep(x1,' ','')
x2 = strrep(x2,' ','')%string replacement
x1_d=double(x1)
x2_d=double(x2)
x1_length=length(x1)
x2_length=length(x2)

maxLength = max([length(x1_d), length(x2_d)])
x1_d(length(x1_d)+1:maxLength) = 0
x2_d(length(x2_d)+1:maxLength) = 0
if x1_d<x1_d
disp('x1 alphabetically procedure x2')

elseif x1_d>x2_d
disp('x2 alpha x1')

else
disp('same')

end

[Stephen23]

"they need to be in a same length otherwise it doesn't work..."

Because lt operates element-wise. More specifically it follows these rules:

https://www.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-operations.html

You also need to read the if documentation carefully, to know how it behaves with a non-scalar condition.

Answer 1

[Stephen23]

Simpler and more robust:

S1 = 'banana';
S2 = 'apple';
[~,X] = sort({S1,S2})
Z = diff(X)

[Ella Yeo]

Thank you,

but what if the user entered the exact same word?

[Stephen23]

"but what if the user entered the exact same word?"

Z = diff(X) * ~strcmp(S1,S2)

returns 0 if the words are the same, otherwise -1 or +1. Or you could use an if:

if strcmp(S1,S2)
...
else
...
end

Answer 2

[Guillaume]

Even simpler, use strings instead of char vector. Comparison operators work on the whole string instead of on characters

S1 = "banana"
S2 = "apple"
S1 < S2     %returns false
S2 == S2    %returns true

So with your code:

x1 = lower(input('Enter a string: ','s'));
x2 = lower(input('Enter a string: ','s'));
x1 = string(x1);
x2 = string(x2);
if x1 < x2
    disp('x1 is before x2 alphabetically')
elseif x1 == x2
    disp('x1 and x2 are identical')
else
    disp('x1 is after x2 alphabetically')
end