public function testCharAt()
{
$str = new Str("Hello, world.");
$this->assertEquals($str->charAt(0), "H");
$this->assertNotEquals($str->charAt(5), " ");
$this->assertEquals($str->charAt($str->length() - 1), ".");
try {
$str->charAt(-1);
} catch (StrIndexOutOfBoundsException $ex1) {
$this->assertEquals(get_class($ex1), 'Str\\StrIndexOutOfBoundsException');
}
try {
$str->charAt($str->length());
} catch (StrIndexOutOfBoundsException $ex2) {
$this->assertEquals(get_class($ex2), 'Str\\StrIndexOutOfBoundsException');
}
}
