Php does not need regular expression collection speed inquiry summary _ PHP Tutorial

Php does not need regular expression collection speed inquiry summary. Note: the following functions do not use regular expressions. The above code is used to retrieve the first matching three functions for the same purpose and copy the code as follows: functionstr_cut ($ str, $ start, $ en note: All the following functions do not use regular expressions.

The above are the three functions that match the first one to achieve the same purpose.

The code is as follows:

Function str_cut ($ str, $ start, $ end) {// obtain the first match, with the highest efficiency. split the string first and then replace it.
$ Content = strstr ($ str, $ start );
$ Content = substr ($ content, strlen ($ start), strpos ($ content, $ end)-strlen ($ start ));
Return $ content;
}
Function str_cut1 ($ str, $ start, $ end) {// retrieve the first match. in efficiency, directly search for replacement.
$ X = strpos ($ str, $ start );
Return substr ($ str, $ x + strlen ($ start), strpos ($ str, $ end)-$ x + strlen ($ end ));
}

Function str_cut3 ($ content, $ start, $ end) {// retrieve the first match. the larger the string, the slower the speed!
$ My = explode ($ start, $ content );
$ My = explode ($ end, $ my [1]);
Return $ my [0];
}

The following are all the three matched functions (all original functions) for the same collection purpose:

The code is as follows:

Function strcut ($ str, $ start, $ end) // The number of first searches, with medium speed
{
If (strpos ($ str, $ start ))
{
$ Sum = substr_count ($ str, $ start );

$ Carr = array ();
For ($ I = 0; $ I <$ sum; $ I ++ ){
$ Str = strstr ($ str, $ start );
$ Str = substr ($ str, strlen ($ start ));
$ Carr [] = substr ($ str, 0, strpos ($ str, $ end ));
}



}
Return $ carr;
}

Function str_cut_all ($ str, $ start, $ end, $ carr = array () // recursion, the slowest running efficiency!
{
If (strpos ($ str, $ start ))
{
$ Str = strstr ($ str, $ start );
$ Str = substr ($ str, strlen ($ start ));
$ Carr [] = substr ($ str, 0, strpos ($ str, $ end ));
If (strpos ($ str, $ start ))
{
Return str_cut_all ($ str, $ start, $ end, $ carr );
}

}
Return $ carr;
}

Function my_Ca ($ content, $ start, $ end) {// retrieve all the matches, which is the fastest efficiency. because the value is read-only once, the larger the string, the more obvious
$ M = explode ($ start, $ content );
$ A = array ();
For ($ I = 1; $ I <count ($ m); $ I ++)
{
$ My = explode ($ end, $ m [$ I]);
$ A [] = $ my [0];
Unset ($ my );
}
Return $;
}

Note my-Ca comparison
Write the following statement:

The code is as follows:

Function my_Ca ($ content, $ start, $ end) {// retrieve all matches
$ M = explode ($ start, $ content );
$ A = array ();
$ Sum = count ($ m );
For ($ I = 1; $ I <$ sum; $ I ++)
{
$ My = explode ($ end, $ m [$ I]);
$ A [] = $ my [0];
Unset ($ my );
}
Return $;
}

Faster!


As can be seen from the above, it is not that the array processing function (explode) is slower than the string processing function (substr, etc.), or that is faster than this, because the array function has more advantages when matching multiple data, the smaller the string to be processed, the smaller the slice. Matching a single string using the cut idea is also the same effect (str_cut ). The key is --- algorithm! The algorithms are well written, and all functions are the same!

Bytes. The above code extracts the first matching three functions to achieve the same purpose: functionstr_cut ($ str, $ start, $ en...