How to check the last char of a string?

Worker Joined: Aug 06, 2004 Posts: 192

I want to check the last character of a string to see if its a certain character. How would I go about this?

Site Admin/Owner Joined: Aug 27, 2002 Posts: 17088

if (substr($string, -1)==$someLetter)) do_something;

Posted: Thu Dec 23, 2004 4:19 pm

Thanks again. RavensScripts

I kinda feel dumb for even asking. Embarassed

Posted: Thu Dec 23, 2004 5:50 pm

Posted: Mon Dec 27, 2004 12:07 pm

Raven one more quick question, is quick why to use that code to check if the last character is in an array of characters?

For example check to see if the latest character is one of these (a,b,e,r)?

Posted: Mon Dec 27, 2004 12:20 pm

Try this (not tested)

$lookFor = array('a','b','e','r');
if (in_array($lookFor,substr($string, -1)))) do_something;

Posted: Mon Dec 27, 2004 12:22 pm

Works perfectly.

Thanks

Posted: Tue Dec 28, 2004 3:31 pm

Raven,

How would I go about checking a string to see if it is in this format, "1,2,3,45"?

The input can be any whole numbers seperated by a commas in a list like above, thats it. Is there a way to check the input to make sure thats all that is entered?

Posted: Tue Dec 28, 2004 6:49 pm

Not knowing exactly what you're after, try this

Code:

if (ereg("(([0-9]+,){4})",$someStr)) echo 'Match';

That is supposed to say, "match any number, followed by a comma, and it can occur up to four times more".

Now if the number of MAX occurences will vary, then we'll have to tweak this.

Posted: Tue Dec 28, 2004 10:01 pm

Well it could be just one number with no comma or any number of occurences. The input could just be say, "1" or "4,8" or "15,6,1,8,5,..."

The numbers represent forum id numbers.

Posted: Tue Dec 28, 2004 10:06 pm

Well, just make the {4} some high number that will never be reached.

Posted: Tue Dec 28, 2004 10:11 pm

So it won't matter if they enter one number with no comma?

Posted: Tue Dec 28, 2004 10:23 pm

Hmmmmm. Good Point. Try this. I know there's probably an easier way but my brain hurts ROTFL

- Regular expressions wear me out! If it doesn't work I'll look at it tomorrow.

Code:

if (ereg("(([0-9]+,){4})",$someStr) OR (ereg("(([0-9]))",$someStr) AND !ereg("(([0-9]+,){4})",$someStr)) echo 'Match';

Posted: Wed Dec 29, 2004 8:44 am

Code:

if (ereg("(([0-9]+,){4})", $forum_ids) OR (ereg("(([0-9]))", $forum_ids) AND !ereg("(([0-9]+,){4})", $forum_ids)))


             {


                        $newfsconfig['forum_ids'] = $forum_ids;


             }


             else


             {


                        die("error");


             }

Here is the code I used to test. The problem is that as long as a number is somewhere in the input it will accept it.

If the user entered "test" they will get the error, however if they entered "1test" is will submit OK.

Posted: Wed Dec 29, 2004 8:47 am

Change

Code:

if (ereg("(([0-9]+,){4})", $forum_ids) OR (ereg("(([0-9]))", $forum_ids) AND !ereg("(([0-9]+,){4})", $forum_ids)))

to

Code:

if (ereg("(([0-9]+,){4})", $forum_ids) OR (ereg("(([0-9]))", $forum_ids) AND !ereg("(([0-9a-zA-Z]+,){4})", $forum_ids)))

Posted: Wed Dec 29, 2004 8:53 am

It still does accepts anyinput as long as a number is in string somewhere.

Posted: Wed Dec 29, 2004 8:55 am

It won't work on unicode/utf-8 because characters above %79 are 2 bytes like %D0%82

So if you do substr($string, -1) you get the %82 which is wrong.
And if you use {4} in a regular expression it has to be multiplied by 2 or less depending on how much unicode characters it has.

Posted: Wed Dec 29, 2004 2:11 pm

if (ereg("^[0-9]+(,[0-9]+)*$"),$forum_ids)) do_something

Posted: Wed Dec 29, 2004 3:39 pm

Thats it!!!!! Wave

I just had to move a " ) "

Code:

if(ereg("^[0-9]+(,[0-9]+)*$", $forum_ids))

I bow to you. Thanks very much.

Posted: Wed Dec 29, 2004 4:21 pm

Actually you want to add an ending ), not move one Smile

Code:

if (ereg("^[0-9]+(,[0-9]+)*$",$forum_ids)) do_something

Posted: Thu Dec 30, 2004 7:45 am

If I use

Code:

if (ereg("^[0-9]+(,[0-9]+)*$"),$forum_ids))

I get this error when the page loads:

Code:

Parse error: parse error, unexpected ',' in /xxxx/xxxxxx/xxxxxx/xxxxxx/xxxxxx/admin/index.php on line 261

The code I changed it to

Code:

if(ereg("^[0-9]+(,[0-9]+)*$", $forum_ids))

Doesn't give the error, am I missing something?

Posted: Thu Dec 30, 2004 9:50 am

No. I just copied it wrong.

Posted: Thu Dec 30, 2004 10:30 am

Ok cool. I can never quite understand regular expression. It really confuses me.

Posted: Thu Dec 30, 2004 10:46 am

^ signifies the start of the pattern

[0-9] means the first character must be numeric and only use the digits 0-9

+ means there can be 1 or more of the preceding item [0-9]

,[0-9] means that if there are more numbers they have to start with a comma and can only contain the digits 0-9

+ means there can be 1 or more numbers proceeded by a comma

* means there is no limit to the pattern

$ signifies the end of the pattern

Posted: Thu Dec 30, 2004 10:53 am

Now it makes sense.