<?php
/**
* Wrapper for strpbrk() except that it accepts a $length parameter
* which will restrict the result string to this many characters.
*
* @param string $haystack The string where char_list is looked for.
* @param string $char_list Case sensitive set of characters to look for.
* @param int $length [optional] If given and is positive, the string returned will contain at most length characters.
* @return false|string
* @throws RangeException
*/
function strpbrkLength( string $haystack, string $char_list, int $length = null ) /*: false|string*/
{
if( null !== $length && 0 > $length )
throw new RangeException( '$length must be null, zero or a positive integer.' );
$strpbrk = strpbrk( $haystack, $char_list );
if( false !== $strpbrk && null !== $length && strlen( $strpbrk ) > $length )
return substr( $strpbrk, 0, $length );
return $strpbrk;
}
$tests = [
[ 'haystack' => '', 'char_list' => 'r+', 'length' => null, 'expect' => false ],
[ 'haystack' => '', 'char_list' => 'r+', 'length' => 0 , 'expect' => false ],
[ 'haystack' => '', 'char_list' => 'r+', 'length' => 1 , 'expect' => false ],
[ 'haystack' => 'r', 'char_list' => 'r+', 'length' => null, 'expect' => 'r' ],
[ 'haystack' => 'r', 'char_list' => 'r+', 'length' => 0 , 'expect' => '' ],
[ 'haystack' => 'r', 'char_list' => 'r+', 'length' => 1 , 'expect' => 'r' ],
[ 'haystack' => 'r+', 'char_list' => 'r+', 'length' => null, 'expect' => 'r+' ],
[ 'haystack' => 'r+', 'char_list' => 'r+', 'length' => 0 , 'expect' => '' ],
[ 'haystack' => 'r+', 'char_list' => 'r+', 'length' => 1 , 'expect' => 'r' ],
[ 'haystack' => 'r+', 'char_list' => 'r+', 'length' => 2 , 'expect' => 'r+' ],
[ 'haystack' => 'w', 'char_list' => 'r+', 'length' => null, 'expect' => false ],
[ 'haystack' => 'w', 'char_list' => 'r+', 'length' => 0, 'expect' => false ],
[ 'haystack' => 'w', 'char_list' => 'r+', 'length' => 1, 'expect' => false ],
[ 'haystack' => 'w+', 'char_list' => 'r+', 'length' => null, 'expect' => '+' ],
[ 'haystack' => 'w+', 'char_list' => 'r+', 'length' => 0 , 'expect' => '' ],
[ 'haystack' => 'w+', 'char_list' => 'r+', 'length' => 1 , 'expect' => '+' ],
];
foreach( $tests as $test => $args )
assert(
strpbrkLength( $args[ 'haystack' ], $args[ 'char_list' ], $args[ 'length' ] ) === $args[ 'expect' ],
"Failed test #$test"
);
preferences:
62.15 ms | 402 KiB | 5 Q