function s($str, $charset = null) {
    return new \Delight\Str\Str($str, $charset);
}

s('Hello w☺rld')
// or
s('Hello w☺rld', 'UTF-8')
// or
s('Hello world', 'ISO-8859-1')

/**
 * Returns whether this string starts with the supplied other string
 *
 * This operation is case-sensitive
 *
 * @param string $prefix the other string to search for
 * @return bool whether the supplied other string can be found at the beginning of this string
 */
public function startsWith($prefix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string starts with the supplied other string
 *
 * This operation is case-insensitive
 *
 * @param string $prefix the other string to search for
 * @return bool whether the supplied other string can be found at the beginning of this string
 */
public function startsWithIgnoreCase($prefix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string contains the supplied other string
 *
 * This operation is case-sensitive
 *
 * @param string $infix the other string to search for
 * @return bool whether the supplied other string is contained in this string
 */
public function contains($infix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string contains the supplied other string
 *
 * This operation is case-insensitive
 *
 * @param string $infix the other string to search for
 * @return bool whether the supplied other string is contained in this string
 */
public function containsIgnoreCase($infix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string ends with the supplied other string
 *
 * This operation is case-sensitive
 *
 * @param string $suffix the other string to search for
 * @return bool whether the supplied other string can be found at the end of this string
 */
public function endsWith($suffix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string ends with the supplied other string
 *
 * This operation is case-insensitive
 *
 * @param string $suffix the other string to search for
 * @return bool whether the supplied other string can be found at the end of this string
 */
public function endsWithIgnoreCase($suffix);


////////////////////////////////////////////////////////////////////////////////


/**
 * Removes all whitespace or the specified characters from both sides of this string
 *
 * @param string $charactersToRemove the characters to remove (optional)
 * @param bool $alwaysRemoveWhitespace whether to remove whitespace even if a custom list of characters is provided (optional)
 * @return static this instance for chaining
 */
public function trim($charactersToRemove = null, $alwaysRemoveWhitespace = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Removes all whitespace or the specified characters from the start of this string
 *
 * @param string $charactersToRemove the characters to remove (optional)
 * @param bool $alwaysRemoveWhitespace whether to remove whitespace even if a custom list of characters is provided (optional)
 * @return static this instance for chaining
 */
public function trimStart($charactersToRemove = null, $alwaysRemoveWhitespace = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Removes all whitespace or the specified characters from the end of this string
 *
 * @param string $charactersToRemove the characters to remove (optional)
 * @param bool $alwaysRemoveWhitespace whether to remove whitespace even if a custom list of characters is provided (optional)
 * @return static this instance for chaining
 */
public function trimEnd($charactersToRemove = null, $alwaysRemoveWhitespace = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the first character or the specified number of characters from the start of this string
 *
 * @param int|null $length the number of characters to return from the start (optional)
 * @return static a new instance of this class
 */
public function first($length = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the last character or the specified number of characters from the end of this string
 *
 * @param int|null $length the number of characters to return from the end (optional)
 * @return static a new instance of this class
 */
public function last($length = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Converts this string to lowercase
 *
 * @return static this instance for chaining
 */
public function toLowerCase();


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string is entirely lowercase
 *
 * @return bool
 */
public function isLowerCase();


////////////////////////////////////////////////////////////////////////////////


/**
 * Converts this string to uppercase
 *
 * @return static this instance for chaining
 */
public function toUpperCase();


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string is entirely uppercase
 *
 * @return bool
 */
public function isUpperCase();


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string has its first letter written in uppercase
 *
 * @return bool
 */
public function isCapitalized();


////////////////////////////////////////////////////////////////////////////////


/**
 * Truncates this string so that it has at most the specified length
 *
 * @param int $maxLength the maximum length that this string may have (including any ellipsis)
 * @param string|null $ellipsis the string to use as the ellipsis (optional)
 * @return static a new instance of this class
 */
public function truncate($maxLength, $ellipsis = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Truncates this string so that it has at most the specified length
 *
 * This method tries *not* to break any words whenever possible
 *
 * @param int $maxLength the maximum length that this string may have (including any ellipsis)
 * @param string|null $ellipsis the string to use as the ellipsis (optional)
 * @return static a new instance of this class
 */
public function truncateSafely($maxLength, $ellipsis = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Counts the occurrences of the specified substring in this string
 *
 * @param string $substring the substring whose occurrences to count
 * @return int the number of occurrences
 */
public function count($substring = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the length of this string
 *
 * @return int the number of characters
 */
public function length();


////////////////////////////////////////////////////////////////////////////////


/**
 * Removes the specified number of characters from the start of this string
 *
 * @param int $length the number of characters to remove
 * @return static a new instance of this class
 */
public function cutStart($length);


////////////////////////////////////////////////////////////////////////////////


/**
 * Removes the specified number of characters from the end of this string
 *
 * @param int $length the number of characters to remove
 * @return static a new instance of this class
 */
public function cutEnd($length);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces all occurrences of the specified search string with the given replacement
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static this instance for chaining
 */
public function replace($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces all occurrences of the specified search string with the given replacement
 *
 * This operation is case-insensitive
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceIgnoreCase($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the first occurrence of the specified search string with the given replacement
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceFirst($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the first occurrence of the specified search string with the given replacement
 *
 * This operation is case-insensitive
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceFirstIgnoreCase($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the specified part in this string only if it starts with that part
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replacePrefix($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the last occurrence of the specified search string with the given replacement
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceLast($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the last occurrence of the specified search string with the given replacement
 *
 * This operation is case-insensitive
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceLastIgnoreCase($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Replaces the specified part in this string only if it ends with that part
 *
 * @param string $searchFor the string to search for
 * @param string $replaceWith the string to use as the replacement (optional)
 * @return static a new instance of this class
 */
public function replaceSuffix($searchFor, $replaceWith = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Splits this string into an array of substrings at the specified delimiter
 *
 * @param string $delimiter the delimiter to split the string at
 * @param int|null $limit the maximum number of substrings to return (optional)
 * @return static[] an array containing the substrings (which are instances of this class as well)
 */
public function split($delimiter, $limit = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Splits this string into an array of substrings at the specified delimiter pattern
 *
 * @param string $delimiterPattern the regular expression (PCRE) to split the string at
 * @param int|null $limit the maximum number of substrings to return (optional)
 * @param int|null $flags any combination (bit-wise ORed) of PHP's `PREG_SPLIT_*` flags
 * @return static[] an array containing the substrings (which are instances of this class as well)
 */
public function splitByRegex($delimiterPattern, $limit = null, $flags = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Splits this string into its single words
 *
 * @param int|null the maximum number of words to return from the start (optional)
 * @return static[] the new instances of this class
 */
public function words($limit = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the part of this string *before* the *first* occurrence of the search string
 *
 * @param string $search the search string that should delimit the end
 * @return static a new instance of this class
 */
public function beforeFirst($search);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the part of this string *before* the *last* occurrence of the search string
 *
 * @param string $search the search string that should delimit the end
 * @return static a new instance of this class
 */
public function beforeLast($search);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the part of this string between the two specified substrings
 *
 * If there are multiple occurrences, the part with the maximum length will be returned
 *
 * @param string $start the substring whose first occurrence should delimit the start
 * @param string $end the substring whose last occurrence should delimit the end
 * @return static a new instance of this class
 */
public function between($start, $end);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the part of this string *after* the *first* occurrence of the search string
 *
 * @param string $search the search string that should delimit the start
 * @return static a new instance of this class
 */
public function afterFirst($search);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns the part of this string *after* the *last* occurrence of the search string
 *
 * @param string $search the search string that should delimit the start
 * @return static a new instance of this class
 */
public function afterLast($search);


////////////////////////////////////////////////////////////////////////////////


/**
 * Matches this string against the specified regular expression (PCRE)
 *
 * @param string $regex the regular expression (PCRE) to match against
 * @param mixed|null $matches the array that should be filled with the matches (optional)
 * @param bool|null $returnAll whether to return all matches and not only the first one (optional)
 * @return bool whether this string matches the regular expression
 */
public function matches($regex, &$matches = null, $returnAll = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string matches the other string
 *
 * @param string $other the other string to compare with
 * @return bool whether the two strings are equal
 */
public function equals($other);


////////////////////////////////////////////////////////////////////////////////


/**
 * Returns whether this string matches the other string
 *
 * This operation is case-sensitive
 *
 * @param string $other the other string to compare with
 * @return bool whether the two strings are equal
 */
public function equalsIgnoreCase($other);


////////////////////////////////////////////////////////////////////////////////


/**
 * Compares this string to another string lexicographically
 *
 * @param string $other the other string to compare to
 * @param bool|null $human whether to use human sorting for numbers (e.g. `2` before `10`) (optional)
 * @return int an indication whether this string is less than (< 0), equal (= 0) or greater (> 0)
 */
public function compareTo($other, $human = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Compares this string to another string lexicographically
 *
 * This operation is case-sensitive
 *
 * @param string $other the other string to compare to
 * @param bool|null $human whether to use human sorting for numbers (e.g. `2` before `10`) (optional)
 * @return int an indication whether this string is less than (< 0), equal (= 0) or greater (> 0)
 */
public function compareToIgnoreCase($other, $human = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Escapes this string for safe use in HTML
 *
 * @return static this instance for chaining
 */
public function escapeForHtml();


////////////////////////////////////////////////////////////////////////////////


/**
 * Normalizes all line endings in this string by using a single unified newline sequence (which may be specified manually)
 *
 * @param string|null $newlineSequence the target newline sequence to use (optional)
 * @return static this instance for chaining
 */
public function normalizeLineEndings($newlineSequence = null);


////////////////////////////////////////////////////////////////////////////////


/**
 * Reverses this string
 *
 * @return static a new instance of this class
 */
public function reverse();


////////////////////////////////////////////////////////////////////////////////


/**
 * Turns this string into an acronym (abbreviation)
 *
 * @param bool|null $excludeLowerCase whether to exclude lowercase letters from the result (optional)
 * @return static a new instance of this class
 */
public function acronym($excludeLowerCase = null);

$length = count($strInstance);
// or
$length = $strInstance->length();
// or
$length = $strInstance->count();

$instances = \Delight\Str\Str::fromArray($arrayOfStrings);