PHP string validation - Firstname_Lastname - php

I'd like to get some help regarding PHP.
Let's say I have a string ($fullname).
I want to validate that it's in the form of "Firstname_Lastname".
For example, make sure that it's "Nathan_Phillips" and not "Nathan Phillips" or "Nathan122" etc.
Can you guys help me with the function?
Thanks in advance! :-)
------------ EDIT -------------
Thank you guys! Managed to do that. Also added the numbers filter. Here's the function:
function isValidName($name)
{
if (strcspn($name, '0123456789') != strlen($name))
return FALSE;
$name = str_replace(" ", "", $name);
$result = explode("_", $name);
if(count($result) == 2)
return TRUE;
else
return FALSE;
}
Usage example:
if(isValidName("Test_Test") == TRUE)
echo "Valid name.";
else
echo "Invalid name.";
Thanks again!

Maybe try something like this:
function checkInput($input) {
$pattern = '/^[A-Za-z]{2,50}_[A-Za-z]{2,50}/';
return preg_match($pattern, substr($input,3), $matches, PREG_OFFSET_CAPTURE);
}
This will accept a string containing 2-50 alphabetic characters, followed by an underscore, followed by 2-50 alphabetic characters.
I'm not the best with regex, so I invite corrections if anyone sees a flaw.
If you have special characters (è, í, etc.), the regex I gave probably won't accept it. Also, it won't accept names like O'Reilly or hyphenated names. See this:
Regex for names
I'll let you track down all the exceptions to the regex for names, but I definitely think regex is the way to go.

Related

How to user pregmatch in php

I am trying to find if a persons name contains any numbers or symbols. I am not very sure how to use preg_match and all the examples online make no sense can someone please explain how i can check if a value has numbers or symbols. And if you can please explain how it works.
To check if the person name contains only number. The code below has been tested and is working
<?php
error_reporting(0);
$number = '001222288';
if (!preg_match('/^[0-9]*$/', $number)) {
//error
echo 'Error does not contain only number';
} else {
echo 'success. it contains only number';
}
?>
if the variable number contains any other thing that is not number it result in error. eg
$number = 'ABFRT001222288';
To check for alphabets or string
<?php
error_reporting(0);
$string = 'ABTYUUU';
if (!preg_match('/^[A-Z]*$/', $string)) {
//error
echo 'Error does not contain only alphabet';
} else {
echo 'success. it contains only alphabets';
}
?>
Mark this as correct answer if it solve your problem
Thanks
The function preg_match use regex expressions. You can use an online tool for test your regex. I use debuggex, preg_match use PCRE expressions. In your case you should, you may use for numbers
preg_match("/[0-9]+/", $subject);
EDIT : We need more details for the symbols you want select

PHP preg_match regex to find letters numbers and spaces?

When people sign up to my site I validate their names with this code:
if (preg_match("[\W]", $name))
{
$mess = $mess . "Your name must contain letters only.<br>";
$status = "NOTOK";
}
This is because your actual name cannot contain symbols unless your parents were drunk when they named you.
However, this regex doesn't detect spaces. How can I fix it?
You can use the following regular expression:
^[\w ]+$
This matches any combinations of word characters \w and spaces , but as the guys said be careful because some names might contain other symbols.
So you can use it like this:
if (preg_match("/^[\\w ]+$/", $name)) {
// valid name
}
else {
// invalid name
}
Try this:
<?php
$user_input = 'User_name';
if (!preg_match('/^[a-z0-9_\s]+$/i', $user_input)) {
// Matches English letters, numbers underscores(_) and spaces
$mess = $mess . "Your name must contain letters only.<br>";
$status = "NOTOK";
}
?>
You just missed regexp separators. I do this sometimes even after 10 years of programming.
if (preg_match("/[\W]/", $name)) ...

check words with preg_match

I have some words with | between each one and I have tried to use preg_match to detect if it's containing target word or not.
I have used this:
<?php
$c_words = 'od|lom|pod|dyk';
$my_word = 'od'; // only od not pod or other word
if (preg_match('/$my_word/', $c_words))
{
echo 'ok';
}
?>
But it doesn't work correctly.
Please help.
No need for regular expressions. The functions explode($delimiter, $str); and in_array($needle, $haystack); will do everything for you.
// splits words into an array
$array = explode('|', $c_words);
// check if "$my_word" exists in the array.
if(in_array($my_word, $array)) {
// YEP
} else {
// NOPE
}
Apart from that, your regular expression would match other words containing the same sequence too.
preg_match('/my/', 'myword|anotherword'); // true
preg_match('/another/', 'myword|anotherword'); // true
That's exactly why you shouldn't use regular expressions in this case.
You can't pass a variable into a string with single quotes, you need to use either
preg_match("/$my_word/", $c_words);
Or – and I find that cleaner :
preg_match('/' .$my_word. '/', $c_words);
But for something as simple as that I don't even know if I'd use a Regex, a simple if (strpos($c_words, $my_word) !== 0) should be enough.
You are using preg_match() the wrong way. Since you're using | as a delimiter you can try this:
if (preg_match('/'.$all_words.'/', $my_word, $c_words))
{
echo 'ok';
}
Read the documentation for preg_match().

String cannot start with zero

I have a string which i want to check with a regex. It is not allowed for it to start with a 0. So please see the following examples:
012344 = invalid
3435545645 = valid
021 = invalid
344545 = valid
etc.
How does this regex look in PHP?
PS. This must be a regex solution!
The REGEX should looks like that :
^[1-9][0-9]*$
PHP Code :
<?php
$regex = "#^[1-9][0-9]*$#";
function test($value, $regex)
{
$text = "invalid";
if(preg_match($regex, $value)) $text = "valid";
return $value+" = "+$text+"\n\r";
}
echo test('012345', $regex);
echo test('12345', $regex);
?>
Well it would be a simple /[1-9][0-9]*/.
Please research your question better next time.
This could have also helped you: Regular expression tester
Edit:
Yeah, the answer got downvoted, because it's missing the anchors and seems to be wrong. For completess' sake, I posted the php code I would use with this regex. And no it's not wrong. It may not be the most elegant way, but I like checking whether the regex matched the whole string afterwards more. One reason is that to debug a regex and see what it actually matched I just have to comment out === $value after return $matches[0]
<?php
function matches($value) {
preg_match("/[1-9][0-9]*/", $value, $matches);
return $matches[0] === $value;
}
//Usage:
if (matches("1234")) {
//...
}
?>

If a variable only contains one word

I would like to know how I could find out in PHP if a variable only contains 1 word. It should be able to recognise: "foo" "1326" ";394aa", etc.
It would be something like this:
$txt = "oneword";
if($txt == 1 word){ do.this; }else{ do.that; }
Thanks.
I'm assuming a word is defined as any string delimited by one space symbol
$txt = "multiple words";
if(strpos(trim($txt), ' ') !== false)
{
// multiple words
}
else
{
// one word
}
What defines one word? Are spaces allowed (perhaps for names)? Are hyphens allowed? Punctuation? Your question is not very clearly defined.
Going under the assumption that you just want to determine whether or not your value contains spaces, try using regular expressions:
http://php.net/manual/en/function.preg-match.php
<?php
$txt = "oneword";
if (preg_match("/ /", $txt)) {
echo "Multiple words.";
} else {
echo "One word.";
}
?>
Edit
The benefit to using regular expressions is that if you can become proficient in using them, they will solve a lot of your problems and make changing requirements in the future a lot easier. I would strongly recommend using regular expressions over a simple check for the position of a space, both for the complexity of the problem today (as again, perhaps spaces aren't the only way to delimit words in your requirements), as well as for the flexibility of changing requirements in the future.
Utilize the strpos function included within PHP.
Returns the position as an integer. If needle is not found, strpos()
will return boolean FALSE.
Besides strpos, an alternative would be explode and count:
$txt = trim("oneword secondword");
$words = explode( " ", $txt); // $words[0] = "oneword", $words[1] = "secondword"
if (count($words) == 1)
do this for one word
else
do that for more than one word assuming at least one word is inputted

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