<?php
$load_error = true;
if ($load_error) {
  exit('error!');
}

if (!in_array($value, array('a','b','c'))) {
  exit("{$value} is not found.");
}

if (strpos('abc', 'a')) {
  exit('exist!');
}

<?php
$fruit = array('apple', 'orange', 'banana');
if (array_search('apple', $fruit)) {
    return true;
} else {
    return false;
}
?>

<?php
if (strpos('abc', 'a') !== false) {
  exit('found!');
}

class example1_controller
{
    function post()
    {  
        $comma_count = 3;
        $filename = __FILE__;
        if (file_exists($filename)) {
            if ($filedata = file_get_contents($filename)) {
                $csv_data = array();
                $rows = explode("\n", $filedata);
                array_shift($rows); //先頭行はタイトルなのでイラネ
                if (count($rows) < 1) {
                    $this->error->addError('parse error.');
                } else {
                    foreach ($rows as $row) {
                        $cols = explode(',', $row);
                        if (count($cols) != 4) {
                            $this->error->addError('invalid column count.');
                            break;
                        }
                        $csv_data[] = $cols;
                    }
                }
            } else {
                $this->error->addError('file read failed.');
            }
        } else {
            $this->error->addError('target file not found.');
        }

        // 途中でエラーがあってもここを通したい
        $this->render->setAttribute('error', $this->error);
        $this->render->setTemplate('test.tpl');
    }
}

class example2_controller
{
    function post()
    {
        $comma_count = 3;
        $filename = __FILE__;

        do {
            if (!file_exists($filename)) {
                $this->error->addError('target file not found.');
                break;
            }

            $filedata = file_get_contents($filename);
            if ($filedata === false) {
                $this->error->addError('file read failed.');
                break;
            }

            $csv_data = array();
            $rows = explode("\n", $filedata);

            array_shift($rows); //先頭行はタイトルなのでイラネ
            if (count($rows) < 1) {
                $this->error->addError('parse error.');
                break;
            }

            foreach ($rows as $row) {
                $cols = explode(',', $row);
                if (count($cols) != 4) {
                    $this->error->addError('invalid column count.');
                    break;
                }
                $csv_data[] = $cols;
            }
        } while(0);

        // 途中でエラーがあってもここを通したい
        $this->render->setAttribute('error', $this->error);
        $this->render->setTemplate('test.tpl');
    }
}