====== PHP RFC: Add str_starts_with(), str_ends_with() and related functions ======
  * Version: 0.4
  * Date: 2016-08-01 (use today's date here) **Updated: 2019-06-18**
  * Author: Will Hudgins, will@wkhudgins.info
  * Status: Declined
  * First Published at: https://wiki.php.net/rfc/add_str_begin_and_end_functions

===== Introduction =====
PHP does not contain functions to test if a string begins or ends with a certain substring. This is currently possible using several other functions, but adding pre-built functions to do this will improve the readability and clarity of PHP code using the function. This feature has been requested multiple times and would be of use to many PHP developers with varying levels of experience. 

===== Proposal =====
Add str_starts_with(), str_starts_with_ci(), str_ends_with(), str_ends_with_ci(), mb_str_starts_with(), mb_str_starts_with_ci(), mb_str_ends_with(), and mb_str_ends_with_ci() functions:

<PHP>
function str_starts_with(string $haystack, string $needle): bool
function str_starts_with_ci(string $haystack, string $needle): bool
function str_ends_with(string $haystack, string $needle): bool
function str_ends_with_ci(string $haystack, string $needle): bool
function mb_str_starts_with(string $haystack, string $needle [, string $encoding]): bool
function mb_str_starts_with_ci(string $haystack, string $needle [, string $encoding]): bool
function mb_str_ends_with(string $haystack, string $needle [, string $encoding]): bool
function mb_str_ends_with_ci(string $haystack, string $needle [, string $encoding]): bool
</PHP>
  
str_starts_with() checks if $haystack begins with $needle. It accomplishes this by comparing each character in $haystack with the corresponding character in $needle. If any of the characters do not match, it will return false. str_ends_with() does the same thing except in reverse: it starts at the end of both $haystack and $needle and compares each character in $haystack to the corresponding character in $needle.

str_starts_with_ci() and str_ends_with_ci() do the same thing, except they are case insensitive.

The mb_* versions of these method function very similar except they make use of the mbfl_strpos() function or the php_mb_stripos() helper function.

Examples below:

<PHP>
$str = "beginningMiddleEnd";
if (str_starts_with($str, "beg"))
    echo "This condition would be true";
if (str_starts_with($str, "Beg"))
    echo "This condition would not be true";
if (str_starts_with_ci($str, "beg"))
    echo "This condition would be true";
if (str_starts_with_ci($str, "Beg"))
    echo "This condition would also be true";
if (str_ends_with($str, "End"))
    echo "This condition would be true";
if (str_ends_with($str, "end"))
    echo "This condition would not be true";
if (str_ends_with_ci($str, "End"))
    echo "This condition would be true";
if (str_ends_with_ci($str, "end"))
    echo "This condition would also be true";
</PHP>

===== Backward Incompatible Changes =====
This could break functions existing in userland with the same names.

===== Proposed PHP Version(s) =====
Next eligible PHP 7.x release.

===== RFC Impact =====
==== To SAPIs ====
Will add the aforementioned functions to all PHP environments.

==== To Existing Extensions ====
Adds mb_str_starts_with(), mb_str_starts_with_ci(), mb_str_ends_with(), and mb_str_ends_with_ci() to the mbstring extension.

==== To Opcache ====
No effect.

==== New Constants ====
No new constants.

==== php.ini Defaults ====
No changed php.ini settings.

===== Open Issues =====
This functionality was requested in both of these bug reports: https://bugs.php.net/bug.php?id=67035 and
https://bugs.php.net/bug.php?id=50434.

===== Unaffected PHP Functionality =====
The PHP string library has been modified. This means that strings.c, basic_functions.c, and php_strings.h have all been modified. Additionally the mbstring library has been modified.

===== Future Scope =====

Once this feature is approved and added, it will not need any future improvements.

===== Vote =====

Voting closes 2019-07-20.

<doodle 
title="Do you want str_starts_with, str_starts_with_ci, str_ends_with, and str_ends_with_ci functions in PHP 7.4?" auth="user" voteType="single" closed="yes">
   * yes
   * no
</doodle>

----

<doodle 
title="Do you want mb_str_starts_with, mb_str_starts_with_ci, mb_str_ends_with, and mb_str_ends_with_ci functions in PHP 7.4?" auth="user" voteType="single" closed="yes">
   * yes
   * no
</doodle>

===== Patches and Tests =====
  * https://github.com/php/php-src/pull/2049

===== Implementation =====
After the project is implemented, this section should contain 
  - the version(s) it was merged to
  - a link to the git commit(s)
  - a link to the PHP manual entry for the feature

===== References =====
Implementation of similar methods/functions in other languages:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith

https://docs.python.org/3/library/stdtypes.html?highlight=startswith#str.startswith

https://docs.python.org/3/library/stdtypes.html?highlight=startswith#str.endswith

https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#startsWith(java.lang.String)

http://ruby-doc.org/core-2.1.1/String.html#method-i-start_with-3F

https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html#startsWithIgnoreCase-java.lang.CharSequence-java.lang.CharSequence-

https://golang.org/pkg/strings/#HasPrefix

https://hackage.haskell.org/package/MissingH-1.4.0.1/docs/Data-String-Utils.html#v:startswith

Related feature request: [[bugid@50434]].

===== Rejected Features =====
Keep this updated with features that were discussed on the mail lists.