Why do I get this response 'Operands to the || and && operators must be convertible to logical scalar values.'?

I wrote this so a user could input a numeric grade and the letter grade would display. I am new to matlab and any help is greatly appreciated.

clear, clc
input('Enter a Grade in Numerical Form?','s');
Grade=ans;
G=Grade;
if G>=90&&G<=100
    fprintf('A\n')
end
if G>=80&&G<90
    fprintf('B\n')
end
if G>=70&&G<80
    fprintf('C\n')
end
if G>=60&&G<70
    fprintf('D\n')
end
if G<60
    fprintf('F\n')
end

[EDITED, Jan, please format your code - thanks!]

Answer 1

[Nirmal]

G=str2num(Grade);

G will be a string so you need to convert that to a number using the str2num function. Its better to use if elseif rather than multiple if statements.

[Philip]

Thanks for the help. I will also change it around if it is better to use if elseif.

Answer 2

[Jan]

G = input('Enter a Grade in Numerical Form?');
if G > 100
  % do nothing
elseif G>=90
    fprintf('A\n')
elseif G>=80
    fprintf('B\n')
elseif G>=70
    fprintf('C\n')
elseif G>=60
    fprintf('D\n')
else
    fprintf('F\n')
end