How to delete the beginning string in php

php method to delete the beginning string: 1. Delete through "substr($str, strlen($prefix));"; 2. Through "preg_replace('/^'. preg_quote($prefix, '/') . '/'...)" method to delete.

The operating environment of this article: Windows 7 system, PHP version 7.1, DELL G3 computer

php Delete a string from the beginning of the string

Specific question:

I have a string that looks like this:

$str = "bla_string_bla_bla_bla";

How do I remove the first bla_; but only if it is in Found the beginning of the string?

Use str_replace(), which deletes all bla_'s.

Method:

Method one:

$prefix = 'bla_';
$str = 'bla_string_bla_bla_bla';
if (substr($str, 0, strlen($prefix)) == $prefix) {
    $str = substr($str, strlen($prefix));
}

Requires: 0.0369 ms (0.000,036,954 seconds)

Method two:

$prefix = 'bla_';
$str = 'bla_string_bla_bla_bla';
$str = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $str);

The first run (compile) takes 0.1749 ms (0.000,174,999 seconds), and then 0.0510 ms (0.000,051,021 seconds).

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to delete the beginning string in php. For more information, please follow other related articles on the PHP Chinese website!