A PHP framework for making it easier to do common string functions

StringPlus.php

<?php
  class StringPlus {
    public $str = '';

    public function __construct($string) {
      // Convert booleans
      if ( $string === true ) {
        $this->str = "true";
      } else if ($string === false) {
        $this->str = "false";

      } else {
        $this->str = strval($string);
      }
    }

    public function __toString() {
      return $this->str;
    }

    public function startsWith($needle, $ignoreCase=false) {
      $haystack = $this;
      $needle = new StringPlus($needle);

      if($ignoreCase) {
        $haystack = $this->lowercase();
        $needle = $needle->lowercase();
      }

      return substr(strval($haystack), 0, $needle->length()) == strval($needle);
    }

    public function endsWith($needle, $ignoreCase=false) {
      $haystack = $this;
      $needle = new StringPlus($needle);

      if ( $ignoreCase ) {
        $haystack = $this->lowercase();
        $needle = $needle->lowercase();
      }

      return substr(strval($haystack), -$needle->length()) == strval($needle);
    }

    public function contains($needle, $ignoreCase=false) {
      $haystack = $this;
      $needle = new StringPlus($needle);

      if ( $ignoreCase ) {
        $haystack = $this->lowercase();
        $needle = $needle->lowercase();
      }

      return strpos(strval($haystack), strval($needle)) !== false;
    }

    public function test($regex) {
      return preg_match($regex, $this->str) === 1;
    }

    public function uppercase() {
      return new StringPlus(strtoupper($this->str));
    }

    public function lowercase() {
      return new StringPlus(strtolower($this->str));
    }

    public function length() {
      return strlen($this->str);
    }
  }
?>

Do whatever the f=== you want with it, whatever personal or commercial, make a million dollars with it, I don't care. It was fun making it, and I hope it can be useful to anyone.

Tests/Usage: https://gist.github.com/C-Bouthoorn/cde2001f3daf6ffadf16e5d0c937681a