I am testing RegExp with online regexr.com tool. I will test string with multiple cases, but I can't get substitution to work.
RexEx for matching string is:
/^[0-9]{1,3}[0-9]{6,7}$/
Which matches local mobile number in my country like this:
0921234567
But then I want to substitute number in this way: add "+" sign, add my country code "123", add "." sign, and then finaly, add matched number with stripped leading zero.
Final number will be:
+385.921234567
I have basic idea to insert matched string, but I am not sure how prepend characters, and strip zero from matched string in following substitution pattern:
\+$&\n\t
I will use PHP preg_replace function.
EDIT:
As someone mentioned wisely, there is posibility that there will be one, two or none of zeros, but I will create separate test cases with regex just testing number of zeroes. Doing so in one regex seems to complicated for now.
Possible numbers will be:
0921234567
00111921234567
Where 111 is country code. I know that some country codes consist of 2 or 3 digits, but I will create special cases, for most country codes.
You can use this preg_replace to strip optional zeroes from start of your mobile #:
$str = preg_replace('~^0*(\d{7,9})$~', '+385.$1', $str);
^[0-9]([0-9]{1,2}[0-9]{6,7})$
You just need to add groups.Replace by +385.$1.See demo.
https://regex101.com/r/cJ6zQ3/22
$re = "/^[0-9]([0-9]{1,2}[0-9]{6,7})$/m";
$str = "0921234567\n";
$subst = "+385.$1";
$result = preg_replace($re, $subst, $str);
I would use a 2-step solution:
Check if we match the main regex
Replace the number by pre-pending + + country code + . + number without leading zeros.
PHP code:
$re = "/^[0-9]{7,10}$/";
$str = "0921234567";
if (preg_match($re, $str, $match)) {
echo "+385." . preg_replace('/^0+/', '', $match[0]);
}
Note that splitting out character class in your regex pattern makes no sense when not using capture groups. ^[0-9]{7,10}$ is the same then as ^[0-9]{1,3}[0-9]{6,7}$, meaning match 7 to 10 digits from start to end of the string.
Leading zeros are easily trimmed from the start with /^0+/ regex.
Related
my string can be
new-york-10036
or
chicago-55036
the desired result is
new-york
chicago
and i basically want to remove all the string that come after the first dash - followed by a number
seems easy but i don't know how
You can use Negative Lookahead, like so:
(.+)(?=\-\d)
The regex reads: "get me everything that is not followed by exactly one dash and exactly one number after that".
Given the input new-york-10036 the regex is going to capture only new-york. In PHP you can get the matched string with:
$string = 'new-york-10036';
$regex = '/(.+)(?=\-\d)/';
preg_match($regex, $string, $return);
echo $return[0] . "\n";
It outputs new-york.
See the regex working here.
Using a regular expression I want to move two letters in a string.
W28
L36
W29-L32
Should be changed to:
28W
36L
29W-32L
The numbers vary between 25 and 44. The letters that need to be moved are always "W" and/or "L" and the "W" is always first when they both exist in the string.
I need to do this with a single regular expression using PHP. Any ideas would be awesome!
EDIT:
I'm new to regular expressions and tried a lot of things without success. The closest I came was using "/\b(W34)\b/" for each possibility. I also found something about using variables in the replace function but had no luck using these.
Your regex \b(W34)\b matches exactly W34 as a whole word. You need a character class to match W or L, and some alternatives to match the numeric range, and use the most of capturing groups.
You can use the following regex replacement:
$re = '/\b([WL])(2[5-9]|3[0-9]|4[0-4])\b/';
$str = "W28\nL36\nW29-L32";
$result = preg_replace($re, "$2$1", $str);
echo $result;
See IDEONE demo
Here, ([WL]) matches and captures either W or L into group 1, and (2[5-9]|3[0-9]|4[0-4]) matches integer numbers from 25 till 44 and captures into group 2. Backreferences are used to reverse the order of the groups in the replacement string.
And here is a regex demo in case you want to adjust it later.
I have strings like this (some examples):
F7998FM3213/02F
J442554NM/05
K439459845/34D
I need to use PHP with preg_replace and regular expressions to delete all non-numeric characters in any string, after the forward-slash, '/'.
For example the codes above would look like this afterwards:
F7998FM3213/02
J442554NM/05
K439459845/34
If you're going for readability, something like this would be perfect:
$parts = explode("/",$line,2);
$parts[1] = preg_replace("/\D/","",$parts[1]);
$output = implode("/",$parts);
However, for conciseness and based entirely on the examples you have given, try this:
$output = preg_replace("/\D+$/","",$input);
This will strip any non-numeric characters from the end of the string, which seems to be what you're after based on your examples.
you can use this:
$subject = <<<LOD
F7998FM3213/02F
J442554NM/05
K439459845/34D
K439459845/34D34
LOD;
echo preg_replace('~^[^/]*+/\K|[^\d\n]++~m', '', $subject);
explanation:
The regex is an alternation between two things:
You match the begining until you encounter / included
the part after the / that is all that is not a digit or a new line one or more times
Since the begining of the string is checked at first, all non digit characters are removed after the /
To remove all \D anywhere after a / you could replace:
(?:/\K|\G(?!^))(\d*)\D+
with $1. Like:
preg_replace(',(?:/\K|\G(?!^))(\d*)\D+,', '$1', $str);
How can I replace a string starting with 'a' and ending with 'z'?
basically I want to be able to do the same thing as str_replace but be indifferent to the values in between two strings in a 'haystack'.
Is there a built in function for this? If not, how would i go about efficiently making a function that accomplishes it?
That can be done with Regular Expression (RegEx for short).
Here is a simple example:
$string = 'coolAfrackZInLife';
$replacement = 'Stuff';
$result = preg_replace('/A.*Z/', $replacement, $string);
echo $result;
The above example will return coolStuffInLife
A little explanation on the givven RegEx /A.*Z/:
- The slashes indicate the beginning and end of the Regex;
- A and Z are the start and end characters between which you need to replace;
- . matches any single charecter
- * Zero or more of the given character (in our case - all of them)
- You can optionally want to use + instead of * which will match only if there is something in between
Take a look at Rubular.com for a simple way to test your RegExs. It also provides short RegEx reference
$string = "I really want to replace aFGHJKz with booo";
$new_string = preg_replace('/a[a-zA-z]+z/', 'boo', $string);
echo $new_string;
Be wary of the regex, are you wanting to find the first z or last z? Is it only letters that can be between? Alphanumeric? There are various scenarios you'd need to explain before I could expand on the regex.
use preg_replace so you can use regex patterns.
$string = "Hot_Chicks_call_me_at_123456789";
How can I strip away so that I only have the numberst after the last letter in the string above?
Example, I need a way to check a string and remove everything in front of (the last UNDERSCORE FOLLOWED by the NUMBERS)
Any smart solutions for this?
Thanks
BTW, it's PHP!
Without using a regular expression
$string = "Hot_Chicks_call_me_at_123456789";
echo end( explode( '_', $string ) );
If it always ends in a number you can just match /(\d+)$/ with regex, is the formatting consistent? Is there anything between the numbers like dashes or spaces?
You can use preg_match for the regex part.
<?php
$subject = "abcdef_sdlfjk_kjdf_39843489328";
preg_match('/(\d+)$/', $subject, $matches);
if ( count( $matches ) > 1 ) {
echo $matches[1];
}
I only recommend this solution if speed isn't an issue, and if the formatting is completely consistent.
PHP's PCRE Regular Expression engine was built for this kind of task
$string = "Hot_Chicks_call_me_at_123456789";
$new_string = preg_replace('{^.*_(\d+)$}x','$1',$string);
//same thing, but with whitespace ignoring and comments turned on for explanations
$new_string = preg_replace('{
^.* #match any character at start of string
_ #up to the last underscore
(\d+) #followed by all digits repeating at least once
$ #up to the end of the string
}x','$1',$string);
echo $new_string . "\n";
To be a bit churlish, your stated specification would suggest the following algorithm:
def trailing_number(s):
results = list()
for char in reversed(s):
if char.isalpha(): break
if char.isdigit(): results.append(char)
return ''.join(reversed(results))
It returns only the digits from the end of the string up to the first letter it encounters.
Of course this example is in Python, since I don't know PHP nearly as well. However it should be easily translated as the concept is easy enough ... reverse the string (or iterate from the end towards the beginning) and accumulate digits until you find a letter and break (or fall out of the loop at the beginning of the string).
In C it would be more efficient to use something a bit like for(x=strlen(s);x>s;x--) to walk backwards through the string, saving a pointer to the most recently encountered digit until we break or drop out of the loop at the beginning of the string. Then return the pointer into the middle of the string where our most recent (leftmost) digit was found.