If loop on ascii code condition not working

Can someone explain to me why the following is happening when I try to run this simple code?

word='[HelloKitty|~123]';
letters= length(word);
x= double(word);
i=1:length(x);
if letters < 4 | 65>x(i) | 90<x(i)<97 | x(i)>122
    disp ('no!!!!')
end

Here is the ascii code matrix for the inputted word: '[HelloKitty|~123]'

>> x(i)

ans =

    Columns 1 through 15

      91    72   101   108   108   111    75   105   116   116   121   124   126    49    50

    Columns 16 through 17

      51    93

Since the word has ascii characters from all ranges (uppercase, lowercase, characters from the 91-96 ascii block, characters and numbers before and after the letter blocks), I'm expecting the IF-loop to show the display message for this word, which does happen.

if letters < 4 | 65>x(i) | 90<x(i)<97 | x(i)>122
    disp ('no!!!!')
end
no!!!!

BUT....if I run the if loop with only one of the conditions specified, it doesn't work for all of them (see below).

if letters < 4 
    disp ('no!!!!')
end
>> if 65>x(i)
    disp ('no!!!!')
end
>> if 90<x(i)<97
    disp ('no!!!!')
end
no!!!!
>> if x(i)>122
    disp ('no!!!!')
end
>>

My question is WHY NOT??? There are characters or numbers in the word that meet each of these conditions, so why do the 65>x(i) condition and the x(i)>122 condition not end up with a display message?

Answer 1

[Walter Roberson]

   90<x(i)<97

means the same as

   ((90<x(i))<97)

which first compares x(i) to 90, giving a result of 0 (false) or 1 (true), and then the expression goes on to compare that 0 or 1 to 97.

I seem to be having difficulty finding any computer languages which do permit the syntax you used?

[Matlab_Novice]

Hello Walter, thanks for your response. So are you suggesting the reason the 90-97 condition works is because my syntax is wrong, and technically none of those conditions should be working? If that is the case, how would you write a code where you're asking to check if a word falls within certain ascii code ranges?

[Walter Roberson]

You can use

90 < x(i) && x(i) < 97

but it would be much more clear to use

ismember(x(i), '[\]^_`')