How do I get my MATLAB code to display an error if the user input number is less than four digits and has less than two distinct numbers?

clear
clc
constant = 6174;            % Initialize end condition of while loop
steps = 0;                 % Initialize steps in a loop

user = input('Please enter a 4 digit number: ')       % User inputs a number
digits = num2str(user);
if numel(num2str(user)) < 4 && length(unique(digits)) < 2{
        disp("Error. Not a valid number. Enter a four digit number with at least two distinct numbers")
        }
end

Answer 1

[Walter Roberson]

user = input('Please enter a 4 digit number: ')       % User inputs a number
digits = num2str(user);
if numel(digits) < 4 || length(unique(digits)) < 2
        error("Error. Not a valid number. Enter a four digit number with at least two distinct numbers");
end

However, you have problems if the user inputs a number starting with 0.

[Richard]

Thank you!

Is there a way to do it with a number with leading zeros?

[Walter Roberson]

digits = input('Please enter a 4 digit number: ', 's');       % User inputs a number
if numel(digits) ~= 4 || length(unique(digits)) < 2 || ~all(isstrprop(digits, 'digit'))
        error("Error. Not a valid number. Enter a four digit number with at least two distinct numbers");
end