public function testCompare() { $str1 = new MString('一二三四五'); $str2 = new MString('一二三四五'); $this->assertEquals(0, $str1->compareTo($str2)); $str2 = $str2->substring(0, 4); $this->assertEquals(1, $str1->compareTo($str2)); $str1 = $str1->substring(0, 1); $this->assertEquals(-1, $str1->compareTo($str2)); }