I have a string that looks like the following:
Security/Flow_Setup/Steady_State/Verification
I only need the first two levels (e.g. Security/Flow_Setup) Is there an easier way to get this. Currently I explode the string into an array using: '/' as a delimiter and then piece together elements 0 and 1.
This works but I was hoping for a more elegant solution.
Any thoughts?
I don't think you can get too much more elegant/short than this if you only need the first two pieces:
list($var1, $var2) = explode('/', $str);
Regex is totally unnecessary here.
Someone mentioned dirname in the comments, which I thought was a clever and probably appropriate idea, and very short and readable (and gets you the string you need instead of two separate parts like the code above):
$str = 'Security/Flow_Setup/Steady_State/Verification';
echo dirname(dirname($str));
// Output: Security/Flow_Setup
I believe that you do everything ok. You can try it this way if you like:
$str = "Security/Flow_Setup/Steady_State/Verification";
echo substr($str, 0, strpos($str, '/', strpos($str, '/') + 1));
(No arrays involved, should be a little bit faster)
not a typical usage nor a string function, but since your string is effectively a path, maybe this would suffice...
dirname(dirname('Security/Flow_Setup/Steady_State/Verification'));
Here is the shortest and most efficient one-liner I can come up with:
$firstTwoParts = implode('/', array_slice(explode('/', $str, 3), 0, 2));
This could be wrapped into a function that let's you control how many parts you want:
function first_n_parts ($str, $n, $delimiter = '/') {
return ($n = (int) $n) ? implode($delimiter, array_slice(explode($delimiter, $str, $n + 1), 0, $n)) : '';
}
...so you can do:
echo first_n_parts($str, 1); // Security
echo first_n_parts($str, 2); // Security/Flow_Setup
echo first_n_parts($str, 3); // Security/Flow_Setup/Steady_State
this regex should do it
'/^([a-zA-Z]+\/[a-zA-Z]+)?/'
Related
How can I use the preg_replace() replace function to only return the parent "component" of a PHP NameSpace?
Basically:
Input: \Base\Ent\User; Desired Output: Ent
I've been doing this using substr() but I want to convert it to regex.
Note: Can this be done without preg_match_all()?
Right now, I also have a code to get all parent components:
$s = '\\Base\\Ent\\User';
print preg_replace('~\\\\[^\\\\]*$~', '', $s);
//=> \Base\Ent
But I only want to return Ent.
Thank you!
As Rocket Hazmat says, explode is almost certainly going to be better here than a regex. I would be surprised if it's actually slower than a regex.
But, since you asked, here's a regex solution:
$path = '\Base\Ent\User';
$search = preg_match('~([^\\\\]+)\\\\[^\\\\]+$~', $path, $matches);
if($search) {
$parent = $matches[1];
}
else {
$parent = ''; // handles the case where the path is just, e.g., "User"
}
echo $parent; // echos Ent
I think maybe preg_match might be a better choice for this.
$s = '\\Base\\Ent\\User';
$m = [];
print preg_match('/([^\\\\]*)\\\\[^\\\\]*$/', $s, $m);
print $m[1];
If you read the regular expression backwards, from the $, it says to match many things that aren't backslashes, then a backslash, then many things that aren't backslashes, and save that match for later (in $m).
How about
$path = '\Base\Ent\User';
$section = substr(strrchr(substr(strrchr($path, "\\"), 1), "\\"), 1);
Or
$path = '\Base\Ent\User';
$section = strstr(substr($path, strpos($path, "\\", 1)), "\\", true);
I want to be able to specify an index in a string and remove it.
I have the following:
"Hello World!!"
I want to remove the 4th index (o in Hello). Here would be the end result:
"Hell World!!"
I've tried unset(), but that hasn't worked. I've Googled how to do this and that's what everyone says, but it hasn't worked for me. Maybe I wasn't using it right, idk.
This is a generic way to solve it:
$str = "Hello world";
$i = 4;
echo substr_replace($str, '', $i, 1);
Basically, replace the part of the string before from the index onwards with the part of the string that's adjacent.
See also: substr_replace()
Or, simply:
substr($str, 0, $i) . substr($str, $i + 1)
$str="Hello World";
$str1 = substr($str,0,4);
$str2 = substr($str,5,7);
echo $str1.$str2;
This php specific of working with strings also bugged me for a while. Of course natural solution is to use string functions or use arrays but this is slower than directly working with string index in my opinion. With the following snippet issue is that in memory string is only replaced with empty � and if you have comparison or something else this is not good option. Maybe in future version we will get built in function to remove string indexes directly who knows.
$string = 'abcdefg';
$string[3] = '';
var_dump($string);
echo $string;
$myVar = "Hello World!!";
$myArray = str_split($myVar);
array_splice($myArray, 4, 1);
$myVar = implode("", $myArray);
Personal I like dealing with arrays.
(Sorry about lack of code brackets putting this up via my phone)
I think can create a function and call it like this
function rem_inx ($str, $ind)
{
return substr($str,0,$ind++). substr($str,$ind);
}
//use
echo rem_inx ("Hello World!!", 4);
I have many strings that follow the same convention:
this.is.a.sample
this.is.another.sample.of.it
this.too
What i want to do is isolate the last part. So i want "sample", or "it", or "too".
What is the most efficient way for this to happen. Obviously there are many ways to do this, but which way is best that uses the least resources (CPU and RAM).
$string = "this.is.another.sample.of.it";
$contents = explode('.', $string);
echo end($contents); // displays 'it'
I realise this question is from 2012, but the answers here are all inefficient. There are string functions built into PHP to do this, rather than having to traverse the string and turn it into an array, and then pick the last index, which is a lot of work to do something quite simple.
The following code gets the last occurrence of a string within a string:
strrchr($string, '.'); // Last occurrence of '.' within a string
We can use this in conjunction with substr, which essentially chops a string up based on a position.
$string = 'this.is.a.sample';
$last_section = substr($string, (strrchr($string, '-') + 1));
echo $last_section; // 'sample'
Note the +1 on the strrchr result; this is because strrchr returns the index of the string within the string (starting at position 0), so the true 'position' is always 1 character on.
http://us3.php.net/strpos
$haystack = "this.is.another.sample.of.it";
$needle = "sample";
$string = substr( $haystack, strpos( $haystack, $needle ), strlen( $needle ) );
Just do:
$string = "this.is.another.sample.of.it";
$parts = explode('.', $string);
$last = array_pop(parts);
$new_string = explode(".", "this.is.sparta");
$last_part = $new_string[count($new_string)-1];
echo $last_part; // prints "sparta".
$string = "this.is.another.sample.of.it";
$result = explode('.', $string); // using explode function
print_r($result); // whole Array
Will give you
result[0]=>this;
result[1]=>is;
result[2]=>another;
result[3]=>sample;
result[4]=>of;
result[5]=>it;
Display any one you want (ex. echo result[5];)
I have strings:
17s 283ms
48s 968ms
The string values are never the same and I want to extract the "second" value from it. In this case, the 17 and the 48.
I'm not very good with regex, so the workaround I did was this:
$str = "17s 283ms";
$split_str = explode(' ', $str);
foreach($split_str as $val){
if(strpos($val, 's') !== false) $sec = intval($val);
}
The problem is, the character 's' exists in both split_str[0] and split_str[1], so my $sec variable keeps obtaining 283, instead of 17.
Again, I'm not very good with regex, and I'm pretty sure regex is the way to go in this case. Please assist. Thanks.
You don't even need to use regex for this.
$seconds = substr($str, 0, strspn($str, '1234567890'));
The above solution will extract all the digits from the beginning of the string. Doesn't matter if the first non-digit character is "s", a space, or anything else.
But why bother?
You can even just cast $str to an int:
$seconds = (int)$str; // equivalent: intval($str)
See it in action.
Regular expressions are definite overkill for such a simple task. Don't use dynamite to drill holes in the wall.
You could do this like so:
preg_match('/(?<seconds>\d+)s\s*(?<milliseconds>\d+)ms/', $var, $matches);
print_r($matches);
If the string will always be formatted in this manner, you could simply use:
<?php
$timeString = '17s 283ms';
$seconds = substr($timeString, 0, strpos($timeString, 's'));
?>
Well, i guess that you can assume seconds always comes before milliseconds. No need for regexp if the format is consistent. This should do it:
$parts = explode(' ', $str);
$seconds = rtrim($parts[0], 's')
echo $seconds; // 17s
This will split the string by space and take the first part 17s. rtrim is then used to remove 's' and you're left with 17.
(\d+s) \d+ms
is the right regexp. Usage would be something like this:
$str = "17s 283ms";
$groups = array();
preg_match("/(\d+)s \d+ms/", $str, $groups);
Then, your number before ms would be $groups[1].
I am trying to extract a substring. I need some help with doing it in PHP.
Here are some sample strings I am working with and the results I need:
home/cat1/subcat2 => home
test/cat2 => test
startpage => startpage
I want to get the string till the first /, but if no / is present, get the whole string.
I tried,
substr($mystring, 0, strpos($mystring, '/'))
I think it says - get the position of / and then get the substring from position 0 to that position.
I don't know how to handle the case where there is no /, without making the statement too big.
Is there a way to handle that case also without making the PHP statement too complex?
The most efficient solution is the strtok function:
strtok($mystring, '/')
NOTE: In case of more than one character to split with the results may not meet your expectations e.g. strtok("somethingtosplit", "to") returns s because it is splitting by any single character from the second argument (in this case o is used).
#friek108 thanks for pointing that out in your comment.
For example:
$mystring = 'home/cat1/subcat2/';
$first = strtok($mystring, '/');
echo $first; // home
and
$mystring = 'home';
$first = strtok($mystring, '/');
echo $first; // home
Use explode()
$arr = explode("/", $string, 2);
$first = $arr[0];
In this case, I'm using the limit parameter to explode so that php won't scan the string any more than what's needed.
$first = explode("/", $string)[0];
What about this :
substr($mystring.'/', 0, strpos($mystring, '/'))
Simply add a '/' to the end of mystring so you can be sure there is at least one ;)
Late is better than never. php has a predefined function for that. here is that good way.
strstr
if you want to get the part before match just set before_needle (3rd parameter) to true
http://php.net/manual/en/function.strstr.php
function not_strtok($string, $delimiter)
{
$buffer = strstr($string, $delimiter, true);
if (false === $buffer) {
return $string;
}
return $buffer;
}
var_dump(
not_strtok('st/art/page', '/')
);
One-line version of the accepted answer:
$out=explode("/", $mystring, 2)[0];
Should work in php 5.4+
This is probably the shortest example that came to my mind:
list($first) = explode("/", $mystring);
1) list() will automatically assign string until "/" if delimiter is found
2) if delimiter "/"is not found then the whole string will be assigned
...and if you get really obsessed with performance, you may add extra parameter to explode explode("/", $mystring, 2) which limits maximum of the returned elements.
The function strstr() in PHP 5.3 should do this job.. The third parameter however should be set to true..
But if you're not using 5.3, then the function below should work accurately:
function strbstr( $str, $char, $start=0 ){
if ( isset($str[ $start ]) && $str[$start]!=$char ){
return $str[$start].strbstr( $str, $char, $start+1 );
}
}
I haven't tested it though, but this should work just fine.. And it's pretty fast as well
You can try using a regex like this:
$s = preg_replace('|/.*$|', '', $s);
sometimes, regex are slower though, so if performance is an issue, make sure to benchmark this properly and use an other alternative with substrings if it's more suitable for you.
Using current on explode would ease the process.
$str = current(explode("/", $str, 2));
You could create a helper function to take care of that:
/**
* Return string before needle if it exists.
*
* #param string $str
* #param mixed $needle
* #return string
*/
function str_before($str, $needle)
{
$pos = strpos($str, $needle);
return ($pos !== false) ? substr($str, 0, $pos) : $str;
}
Here's a use case:
$sing = 'My name is Luka. I live on the second floor.';
echo str_before($sing, '.'); // My name is Luka
$arr = explode("/", $string, 2); $first = $arr[0];
This Way is better and more accurate than strtok
because if you wanna get the values before # for example
while the there's no string before # it will give you whats after the sign .
but explode doesnt
$string="kalion/home/public_html";
$newstring=( stristr($string,"/")==FALSE ) ? $string : substr($string,0,stripos($string,"/"));
why not use:
function getwhatiwant($s)
{
$delimiter='/';
$x=strstr($s,$delimiter,true);
return ($x?$x:$s);
}
OR:
function getwhatiwant($s)
{
$delimiter='/';
$t=explode($delimiter, $s);
return ($t[1]?$t[0]:$s);
}