How to count digits of a number in easy way?

Hi first of all I am a beginner :D

I don't know much about matlab.

I want to know how can you count digits of a number in matlab in an easy way.

i found this :

A=input('enter a number');
max(ceil(log10(abs(A))),1)

But I'm not allowed to use it.

It should be easy and should containing while,if,...

I have tried myself:

clc
x=input('Enter Number A= ');
t=0;
x=x/10;
t=t+1;
while x<0
    if x>0
        x=x/10; 
        t=t+1;
    end
end

disp(t)

__________

But it won't work!

can you guys please help me?

by the way the question I want to write the code for it is input 7 numbers then count digits of them and show.

thankssss a lot

[Benjamin Großmann]

Your code does nothing useful when the user inputs positive values or zero (while x<0) and runs infinitely (useful?) when the user inputs negative values (while x<0... if x>0...).

The answer to your question depends on what kind of numbers you want to consider. Natural number, integer, real number?

[Mahbod Q]

I should write a program that gets 7 natural numbers and count the digits of them then display them.

[Jan]

@Mahbod Q: You got 4 useful answers already. Do they work for you?

Answer 1

[Jan]

Of course log10 is the perfect method. That you are "not allowed to use it" sounds like one of the typical homework questions, when teachers try to force students to find solutions apart from the obvious and efficient built-in methods. As soon as your schooling is finished, this will be completely useless. So keep in mind, that log10 is the best solution. An now try it with a wooden hammer...

while x<0
  if x>0

This cannot work. Do you mean positive numbers? Then you can run a loop like "while x > 1".

x = input('Enter Number A= ');
t = 0;
while x > 1
  x = x / 10
  t = t + 1
end
disp(t)

I've only removed some lines from your code. What do you observe? Do you need to adjust some parameters? Try it with 1, 2, 9, 10, 11, 99, 100, 101 and so on.

Note, that I have have not written a solution of your homework (it would be cheating to submit it), but that I've taken all lines from your suggestion and just changed "< 0" to "> 1".

[Mahbod Q]

thank you a lot. I tried it it works , but it displays "t" two times at the end, whats the problem?

Answer 2

[James Tursa]

See these related posts:

https://www.mathworks.com/matlabcentral/answers/142819-how-to-find-number-of-significant-figures-in-a-decimal-number

https://www.mathworks.com/matlabcentral/answers/184255-how-to-calculate-digits-after-decimal-point