I need to check a string to determine if it contains any characters other than |, in order to assign those variables that have nothing except | a value of NULL (there could be theoretically any number of | characters but it likely will not be more than 5-6). Like ||||
I could see looping through each character of the string or somesuch, but I feel there must be a simpler way.
if (preg_match('/[^|]/', $string)) {
// string contains characters other than |
}
or:
if (strlen(str_replace('|', '', $string)) > 0) {
// string contains characters other than |
}
Yes, you can use regular expressions:
if(! preg_match('/[^\|]/', $string)) {
$string = NULL;
}
I wanted to check if a string only contains certain characters. To prevent double negation (because I find them harder te read) I decided to use the following regex:
preg_match('/^[|]+$/', $string)
This checks a string from beginning to end to only contain | characters (at least one).
If the string has length after trimming pipes from the front of the string, then it has at least one non-pipe character.
if (strlen(ltrim($string, '|')) {
// has non-pipe characters
}
Fastest and simplest way is possibly the stripos function. It returns the position of a string inside another, or false if it can't be found:
if (false === stripos($string, '|')) {
$string = null;
}
The false === is needed for strict type comparison, since stripos could return a zero indicating that the | is on the first char.
You can use a more sophisticated validation engine that makes reading easier. I do recommend Respect\Validation. Usage sample:
if (v::not(v::contains('|'))->validate($string)) {
$string = null;
}
Related
Can we use Bitwise operator "|" with strpos in php?
I need to check if a0,a1,a2,a5 strings are exists in the given $status variable.
My code is given bellow.My code will return values(position) only when the status variable have value=a0 or a1 or a2 or a5.It will return false when $status='a1 test string.
$status='a1 test string';
echo strpos("|a0|a1|a2|a5|", $status);
No, you cannot. Documentation does not mention anything remotely similar:
strpos — Find the position of the first occurrence of a substring in
a string
Find the numeric position of the first occurrence of needle in the
haystack string.
Parameters
haystack The string to search in.
needle If needle is not a string, it is converted to an integer and
applied as the ordinal value of a character.
offset If specified, search will start this number of characters
counted from the beginning of the string. If the offset is negative,
the search will start this number of characters counted from the end
of the string.
In fact, it wouldn't make much sense to implement such feature since you already have a full-fledged regular expression engine:
$has_substrings = (bool)preg_match('/a0|a1|a2|a5/u', $status);
You can use it like this. Here | means or
<?php
$status='a1 test string';
if(preg_match("/\b(a0|a1|a2|a5)\b/", $status))
{
echo "Matched";
}
Can we use Bitwise operator "|" with strpos in php?
as a Bitwise operator | - No
as a literal symbol | - Yes
You cannot do that with a single string search. You need to use either a regular expression which can test for multiple options at once, or you need to iterate over your search terms.
Sahil Gulati gave a simple example for a regular expression based approach.
Here is a simple iteration based approach:
<?php
$status = 'a1 test string';
$search = explode('|', substr("|a0|a1|a2|a5|", 1, -1));
// would be much easier to start with an array of search tokens right away:
// $search = ['a0', 'a1', 'a2', 'a5'];
$result = false;
array_walk($search, function($token) use ($status, &$result) {
$result = (FALSE!==strpos($status, $token)) ? true : $result;
});
var_dump($result);
I have a function which will return true if input is pure numeric or alphabate else it will return false. This function is working fine.
function checktype($a)
{
if (preg_match('/^\d+$/', $a)) { //check numeric (can use other numeric regex also like /^[0-9]+$/ etc)
$return = true;
} else if (preg_match('/^[a-zA-Z]+$/', $a)) { //check alphabates
$return = true;
} else { //others
$return = false;
}
return $return;
}
var_dump(checktype('abcdfekjh')); //bool(true)
var_dump(checktype('1324654')); //bool(true)
var_dump(checktype('1324654hkjhkjh'));//bool(false)
No I tried to optimized this function by removing conditions so I modified code to:
function checktype($a)
{
$return = (preg_match('/^\d+$/', $a) || preg_match('/^[a-zA-Z]+$/', $a)) ? true:false;
return $return;
}
var_dump(checktype('abcdfekjh')); //bool(true)
var_dump(checktype('1324654')); //bool(true)
var_dump(checktype('1324654hkjhkjh'));//bool(false)
Now in third step I tried to merge both regex in single regex so I can avoid two preg_match function and got stuck here:
function checktype($a)
{
return (preg_match('regex to check either numeric or alphabates', $a)) ? true:false;
}
I tried a lot of combinations since 2 days by using OR(!) operator using not operator(?!) but no success at all.
Below some reference website from which i pick expression and made some combinations:
http://regexlib.com/UserPatterns.aspx?authorid=26c277f9-61b2-4bf5-bb70-106880138842
http://www.rexegg.com/regex-conditionals.html
OR condition in Regex
Regex not operator (come to know about NOT operator)
https://www.google.co.in/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=regular+expression+not+condition (come to know about NOT operator)
So here main question is, is there any single regex pattern to check string contains pure numeric value or pure alphabates?
Note: Alternative solution can be check string is alphanumeric and then return true or false accordingly. Also php inbuilt function like is_numeric and is_string can be used, but I am more curious to know the single regex pattern to check weather string conains pure numeric digit or pure alphaba digits.
A one regex to check if a string is all ASCII digits or all ASCII letters is
'/^(?:\d+|[a-zA-Z]+)$/'
See regex demo
This regex has two things your regexps do not have:
a grouping construct (?:....)
an alternation operator |.
Explanation:
^ - start of string
(?:\d+ - one or more digits
| - or...
[a-zA-Z]+) - one or more ASCII letters
$ - end of string
If you need to make it Unicode-aware, use [\p{L}\p{M}] instead of [a-zA-Z] (and \p{N} instead of \d, but not necessary) and use the /u modifier:
'/^(?:\p{N}+|[\p{L}\p{M}]+)$/u'
And in case you want to really check that from the beginning to end, use
'/\A(?:\p{N}+|[\p{L}\p{M}]+)\z/u'
^^ ^^
or
'/^(?:\p{N}+|[\p{L}\p{M}]+)$/Du'
The $ without /D modifier does not match the string at its "very end", it also matches if there is a newline after it as the last character.
I have some PHP code that accepts an uploaded file from an HTML form then reads through it using regex to look for specific lines (in the case below, those with "Number" followed by an integer).
The regex matches the integers like I want it to, but of course they're returned as strings in $matches. I need to check if the integer is between 0 and 9 but I um unable to do this no matter what I try.
Using intval() or (int) to first convert the matches to integers always returns 0 even though the given string contains only integers. And using in_array to compare the integer to an array of 0-9 as strings always returns false as well for some reason. Here's the trouble code...
$myFile = file($myFileTmp, FILE_IGNORE_NEW_LINES);
$numLines = count($myFile) - 1;
$matches = array();
$nums = array('0','1','2','3','4','5','6','7','8','9');
for ($i=0; $i < $numLines; $i++) {
$line = trim($myFile[$i]);
$numberMatch = preg_match('/Number(.*)/', $line, $matches);
if ($numberMatch == 1 and ctype_space($matches[1]) == False) { // works up to here
$number = trim($matches[1]); // string containing an integer only
echo(intval($number)); // conversion doesn't work - returns 0 regardless
if (in_array($number,$nums)) { // searching in array doesn't work - returns FALSE regardless
$number = "0" . $number;
}
}
}
I've tried type checking, double quotes, single quotes, trimming whitespace, UTF8 encoding...what else could it possibly be? I'm about to give up on this app entirely, please save me.
Use '===' for eq for example
if 1 == '1' then true;
if 1 === '1' false;
if 1 == true then true;
if 1 === true then false
You can show file?
You write in your question that you're using a regular expression to look for the term "Number" followed by a single digit (0-9).
A regular expression for it would be:
/Number(\d)/
It will contain in the matching group 1 the number (digit) you're looking for.
The pattern you use:
/Number(.*)/
can contain anything (but a line-break) in the first matching group. It obviously is matching too much. You then have a problem filtering that too much retro-actively.
It normally works best to first look as precise as possible than to fiddle with too much noise afterwards.
I have many headlines in my project like:
00.00.2014 - Headline Description e.t.c.
I want to check with php if the given strings contain the format 00.00.0000 - in front. The part after the - doesn't matter.
Can someone help me with something like:
$format = '00.00.0000 -';
if ($string MATCHES $format IN FRONT) {
// ...some code...
}
This should work:
if (preg_match("/^\d{2}\.\d{2}\.\d{4}\s\-\s.*$/", $string) === 1) {
// $string matches!
}
Explanation:
^ is "the beginning of the string"
\d is any digit (0, 1, 2, ..., 9)
{n} means "repeated n times"
\. is a dot
\s is a space
\- is a minus sign
. is "any single character"
* means "repeated 0 or more times`
$ means "end of the string"
I don't have a dev environment to test this out on but i'll give you some psuedocode:
I'm unsure of the context, but you can test this function on any given STRING:
Function:
Boolean hasCorrectFormat($myString){
//Here take the string and cut it into a char array.
$charArray = str_split($myString);
//This will give you a char array. Compare the first 12 elements of this
//array to see if they are correct. If its supposed to be number make
//sure it is, if its supposed to be a "." make sure it is..etc
//"00.00.0000 -" is 12 characters.
if(!isNumeric(charArray[0])){
return false;
}
else if(!isNumeric(charArray[1])){
return false;
}
else if(charArray[2] != "."){
return false;
}
//so on and so forth.....
else {return true}
}
Like i said i can't test this, and i can almost guarantee you this code wont run. This should give you the logic involved though.
Edit: also i wrote this assuming you dont literally mean "00.00.0000" but rather "xx.xx.xxxx" x being any number 0-9. If you need to make sure it is literally zeros then just cut your string to be the first ten chars and compare it.
Use the strpos function. Something like this:
if (strpos($string,'00.00.0000 -') !== true) {
//some code
}
I'm trying to port this java to php:
String _value = '1111122222';
if (_value.matches("(1{5}|2{5}|3{5}|4{5}|5{5}|6{5}|7{5}|8{5}|9{5}){2}")) {
// check for number with the same first 5 and last 5 digits
return true;
}
As the comment suggests, I want to test for a string like '1111122222' or '5555566666'
How can I do this in PHP?
Thanks,
Scott
You can use preg_match to do so:
preg_match('/^(1{5}|2{5}|3{5}|4{5}|5{5}|6{5}|7{5}|8{5}|9{5}){2}$/', $_value)
This returns the number of matches (i.e. either 0 or 1) or false if there was an error. Since the String’s matches method returns only true if the whole string matches the given pattern but preg_match doesn’t (a substring suffices), you need to set markers for the start and the end of the string with ^ and $.
You can also use this shorter regular expression:
^(?:(\d)\1{4}){2}$
And if the second sequence of numbers needs to be different from the former, use this:
^(\d)\1{4}(?!\1)(\d)\2{4}$
Well, you could do:
$regex = '/(\d)\1{4}(\d)\2{4}/';
if (preg_match($regex, $value)) {
return true;
}
Which should be much more efficient (and readable) than the regex you posted...
Or, an even shorter (and potentially cleaner) regex:
$regex = '/((\d)\2{4}){2}/';
$f = substr($_value, 0, 5);
$s = substr($_value, -5);
return (substr_count($f, $f[0]) == 5 && substr_count($s, $s[0]) == 5);
Conversion is below. preg_match() is the key: http://www.php.net/preg_match
$value = '1111122222';
if (preg_match('/^(1{5}|2{5}|3{5}|4{5}|5{5}|6{5}|7{5}|8{5}|9{5}){2}$/', $value)) {
// check for number with the same first 5 and last 5 digits
return true;
}