How to check the first 2 characters ( case-insensitive ) in PHP? - php

I have a search input box.
I already check for the first 2 characters.
$first_two = substr($search,0,2);
They need to start with BS, so I check them like this :
if ($search AND $first_two == 'bs' ){
// ... do stuffs
}
After that, I just realize that I don't want to have any restriction on them.
I want my first two character is case-insensitive.
I want to allow BS, Bs, bs and bS.
What do I need to fix in my if (?) to allow these to happens ?

Use a certain case for your comparison, this example uses lower case
$first_two = substr($search,0,2);
if ($search AND strtolower($first_two) == 'bs' ){
// ... do stuffs
}
This way BS, Bs, bS will all be converted to bs and your comparison will always work

Use strcasecmp() like this:
if ($search AND strcasecmp($first_two , "bs") == 0)
//^If both strings are the same (case-insensitive) the function returns 0

Related

preg_match admits only two consecutive lowercases

I want to check if password contains:
minimum 2 lower cases
minimum 1 upper case
minimum 2 selected special characters
The problem is that when i want to verify this,it admits two lowercases,but only if they are consecutive,like this:paSWORD .
if I enter pASWORd,it returns an error.
This is the code
preg_match("/^(?=.*[a-z]{2})(?=.*[A-Z])(?=.*[_|!|#|#|$|%|^|&|*]{2}).+$/")
I don't see where the problem is and how to fix it.
You're looking for [a-z]{2} in your regex. That is two consecutive lowercases!
I will go out on a limb and suggest that it is probably better to individually check each of your three conditions in separate regexes rather than trying to be clever and do it in one.
I've put some extra braces in which may get your original idea to work for non-consecutive lowercase/special chars, but I think the expression is overcomplex.
preg_match("/^(?=(.*[a-z]){2})(?=.*[A-Z])(?=(.*[_!##$%^&*]){2}).+$/")
You can use this pattern to check the three rules:
preg_match("/(?=.*[a-z].*[a-z])(?=.*[A-Z])(?=.*[_!##$%^&*].*[_!##$%^&*])/");
but if you want to allow only letters and these special characters, you must add:
preg_match("/^(?=.*[a-z].*[a-z])(?=.*[A-Z])(?=.*[_!##$%^&*].*[_!##$%^&*])[a-zA-Z_!##%^&*]+$/");
a way without regex
$str = '*MauriceAimeLeJambon*';
$chars = 'abcdefghijklmnopqrtuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_!##$%^&*';
$state = array('lower' => 2, 'upper' => 1, 'special' => 2);
$strlength = strlen($str);
for ($i=0; $i<$strlength; $i++) {
$pos = strpos($chars, $str[$i]);
if (is_numeric($pos)) {
if ($state['lower'] && $pos<26) $state['lower']--;
elseif ($state['upper'] && $pos<52) $state['upper']--;
elseif ($state['special']) $state['special']--;
} else { $res = false; break; }
$res = !$state['lower'] && !$state['upper'] && !$state['special'];
}
var_dump($res);
(This version give the same result than the second pattern. If you want the same result than the first pattern, just remove the else {} and put the last line out of the for loop.)

Password Validation With Multiple Rules

I'm attempting to write a regex in PHP that validates the following:
At least 10 chars
Has at least 2 Upper-case characters
Has at least 2 Numbers OR Symbols
I've looked at just about every reference I can find but, to no avail.
I guess I can test individually, but that makes me very sad :(
Can someone please help? (And send me to a spot where I can learn in plain English Reg Ex?)
This picture is worth more than 1000 words
(and that's a lot of entropy)
(image via XKCD)
With this in mind you might want to consider dropping rules 2 & 3 if password length is higher than X (say.. 20) or increase the minimum to at least 16 characters (as the only rule).
As for your requirement:
As opposed to having one big, ugly, hard-to-maintain, advanced RegExp you might want to break the problem in smaller parts and tackle each bit separately using dedicated functions.
For this you could look at ctype_* functions, count_chars() and MultiByte String Functions.
Now the ugly:
This advanced RegEx will return true or false according to your rules:
preg_match('/^(?=.{10,}$)(?=.*?[A-Z].*?[A-Z])(?=.*?([\x20-\x40\x5b-\x60\x7b-\x7e\x80-\xbf]).*?(?1).*?$).*$/',$string);
Test demo here: http://regex101.com/r/qE9eB2
1st part (LookAhead) : (?=.{10,}$) will check string length and continue if it has at least 10 characters. You could drop this and do a check with strlen() or even better mb_strlen().
2nd part (also a LookAhead): (?=.*?[A-Z].*?[A-Z]) will check for the presence of 2 UPPERCASE characters. You could also do a $upper=preg_replace('/[^A-Z]/','',$string) instead and count the chars in $upper to be more than two.
3rd LookAhead uses a character class: [\x20-\x40\x5b-\x60\x7b-\x7e\x80-\xbf] with hex escaped character ranges for common symbols (pretty much all the symbols one could find on an average keyboard). You could also do a $sym=preg_replace('/[^a-zA-Z]/','',$string) instead and count the chars in $sym to be more than two. Note: to make it shorter I used a recursive group (?1) to not repeat the same character class again
For learning, the most comprehensive RegExp reference I know of is: regular-expressions.info
You can use lookaheads to make sure that what you are looking for is contained appropriately.
/(?=.*[A-Z].*[A-Z])(?=.*[^a-zA-Z].*[^a-zA-Z]).{10,}/
I have always preferred good old procedural code for handling stuff like this. Regular expressions can be useful but they can also be a little cumbersome, especially for code maintenance and quick scanning (regular expressions are not exactly examples of readability).
function strContains($string, $contains, $n = 1, $exact = false) {
$length = strlen($string);
$tally = 0;
for ($i = 0; $i < $length; $i++) {
if (strpos($contains, $string[$i]) !== false) {
$tally++;
}
}
return ($exact ? $tally == $n : $tally >= $n);
}
function validPassword($password) {
if (strlen($password) < 10) {
return false;
}
$upperChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$upperCount = 2;
if (strContains($password, $upperChars, $upperCount) === false) {
return false;
}
$numSymChars = '0123456789!"#$%&\'()*+,-./:;<=>?#[\\]^_`{|}~';
$numSymCount = 2;
if (strContains($password, $numSymChars, $numSymCount) === false) {
return false;
}
return true;
}

Regular Expression (avoid float numbers)

I want a pattern to create a "is_id()" function to validate user input before mysql query. The pattern most contain ONLY numbers, my problem is avoid the float numbers:
function is_id($id) {
$pattern = "/^[0-9]+/";
if(preg_match($pattern,$id)) {
echo "ok";
} else {
echo "error";
}
}
is_id(0) // error
is_id(-5) // error
is_id(-5.5) // error
is_id(1.5) // ok <-- THIS IS THE PROBLEM
is_id(10) // ok
is_id("5") // ok
is_id("string") // error
$ denotes the end of a line/string to match.
/^[0-9]+$/
You're missing the trailing $ in your pattern. In is_id(1.5) your pattern is matching the 1 and stopping. If you add a trailing $ (as in ^[0-9]+$) then the pattern will need to match the entire input to succeed.
Why use a regex? Why not check types (this isn't as tiny as the regex, but it may be more semantically appropriate)
function is_id($n) {
return is_numeric($n) && floor($n) == $n && $n > 0;
}
is_numeric() verifies that it's either a float, an int, or a number than can be converted.
floor($n) == $n checks to see if it's indeed an integer.
$n > 0 checks to see if it's greater than 0.
Done...
You don't need regex for this, you can use a simple check like so:
function is_id($id)
{
return ((is_numeric($id) || is_int($id)) && !is_float($id)) && $id > -1
}
The output is as follows:
var_dump(is_id(0)); // false - are we indexing from 0 or 1 ?
var_dump(is_id(-5)); // false
var_dump(is_id(-5.5)); // false
var_dump(is_id(1.5)); // false
var_dump(is_id(10)); // true
var_dump(is_id("5")); // true
var_dump(is_id("string")); // false
I favour ircmaxell's answer.

How to convert some character into numeric in php?

I need help to change a character in php.
I got some code from the web:
char dest='a';
int conv=(int)dest;
Can I use this code to convert a character into numeric? Or do you have any ideas?
I just want to show the result as a decimal number:
if null == 0
if A == 1
Use ord() to return the ascii value. Subtract 96 to return a number where a=1, b=2....
Upper and lower case letters have different ASCII values, so if you want to handle them the same, you can use strtolower() to convert upper case to lower case.
To handle the NULL case, simply use if($dest). This will be true if $dest is something other than NULL or 0.
PHP is a loosely typed language, so there is no need to declare the types. So char dest='a'; is incorrect. Variables have $ prefix in PHP and no type declaration, so it should be $dest = 'a';.
Live Example
<?php
function toNumber($dest)
{
if ($dest)
return ord(strtolower($dest)) - 96;
else
return 0;
}
// Let's test the function...
echo toNumber(NULL) . " ";
echo toNumber('a') . " ";
echo toNumber('B') . " ";
echo toNumber('c');
// Output is:
// 0 1 2 3
?>
PS:
You can look at the ASCII values here.
It does indeed work as in the sample, except that you should be using php syntax (and as a sidenote: the language that code you found most probably was, it did not do the same thing).
So:
$in = "123";
$out = (int)$in;
Afterwards the following will be true:
$out === 123
This may help you:
http://www.php.net/manual/en/function.ord.php
So, if you need the ASCII code you will need to do:
$dest = 'a';
$conv = ord($dest);
If you want something like:
a == 1
b == 2
.
.
.
you should do:
$dest = 'a';
$conv = ord($dest)-96;
For more info on the ASCII codes: http://www.asciitable.com/
And for the function ord: http://www.php.net/manual/en/function.ord.php
It's very hard to answer because it's not a real question but just a little bit of it.
But if you ask.
It seems you need some translation table, that defines links between letters and numbers
A -> 2
B -> 3
C -> 4
S -> 1
or whatever.
You can achieve this by using an array, where keys would be these letters and values - desired numbers.
$defects_arr = array(
'A' -> 2,
'B' -> 3,
'C' -> 4'
'S' -> 1
};
Thus, you can convert these letters to numbers
$letter = 'A';
$number = $defects_arr($letter);
echo $number; // outputs 1
But it still seems is not what you want.
Do these defect types have any verbose equivalents? If so, why not to use them instead of letters?
Telling the whole story instead of little bit of it will help you to avoid mistakes and will save a ton of time, both yours and those who to answer.
Out of this question, if you are looking for convert RT0005 to 5
$max = 'RT0005';
return base_convert($max,10,10);
// return 5

how can i verify phone number with php

i have a phone number in following format +923334173333 and now i want to validate this number exactly in the given format and length with php
Fastest way would be
function validatePhoneNumber($n)
{
return strlen($n) == 13 && $n[0] == '+' && ctype_digit(substr($n, 1)) == 13;
}
validatePhoneNumber('+923334173333'); // returns true
You would need the rules for all possible types of phone numbers and their limitation in the whole world. I'm uncertain if such list even exists.
You can test the length with strlen(), and use ctype_digit() in combination with substr() to check that the substring starting after the '+' consists only of digits.

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