# [MATLAB] IsNum, IsAlpha, IsAlphaNum

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## 0 Replies - 1129 Views - Last Post: 05 September 2016 - 04:50 PM

### #1 NeoTifa

• NeoTifa Codebreaker, the Scourge of Devtester

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# [MATLAB] IsNum, IsAlpha, IsAlphaNum

Posted 05 September 2016 - 04:50 PM

Nothing much, just something small but it's handy. Since they're so tiny, I'm putting all 3 in the same snippet. Just do me a favor, if you use it, give me credit (although something so tiny is pretty basic).

IsNum
```function [ isnum ] = IsNum ( c )
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% IsNum - Returns true if char c is a number
%
% Determines whether c is a number or not
% Author: NeoTifa @ dreamincode.net
%
% example: c = '1' -> true/1, c = 'a' -> false/0
%
% args:
% c - char to check
%
% rets:
% isnum - true/1 if c is a number, false/0 otherwise
%
% Assumptions:
% - c is a single character
% - c is ASCII
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

isnum = (c >= '0') && (c <= '9');

end

```

IsAlpha
```function [ isalpha ] = IsAlpha ( c )
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% IsAlpha - Returns true if char c is an alphabetical letter
%
% Determines whether c is a letter or not
% Author: NeoTifa @ dreamincode.net
%
% example: c = 'a' -> true/1, c = '1' -> false/0
%
% args:
% c - char to check
%
% rets:
% isalpha - true/1 if c is an alpha letter, false/0 otherwise
%
% Assumptions:
% - c is a single character
% - c is ASCII
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

isalpha = ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));

end

```

IsAlphaNum
```function [ isalphanum ] = IsAlphaNum ( c )
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% IsAlpha - Returns true if char c is an alphanumerical character
%
% Determines whether c is a letter or a number.
% Author: NeoTifa @ dreamincode.net
%
% example: c = 'a' -> true/1, c = '1' -> true/1, c = ',' -> false/0
%
% args:
% c - char to check
%
% rets:
% isalphanum - true/1 if c is an alphanumerical char, false/0 otherwise
%
% Assumptions:
% - c is a single character
% - c is ASCII
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

isalphanum = ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z')) || ((c >= '0') && (c <= '9'));

end

```

This post has been edited by NeoTifa: 11 September 2016 - 10:47 AM

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