PHP null

 ~ $ php main.php

Gold Medal

Fatal error: Uncaught TypeError: Return value of getAward() must be of the type string, null returned in /home/dotinstall/main.php:7

Stack trace:

#0 /home/dotinstall/main.php(11): getAward(40)

#1 {main}

  thrown in /home/dotinstall/main.php on line 7

~ $ php main.php

Gold Medal

~ $ php main.php

Gold Medal

~ $ 

<?php

declare(strict_types=1);

function getAward(?int $score): ?string

{

  return $score >= 100 ? ‘Gold Medal’ : null;

}

echo getAward(150) .PHP_EOL;

echo getAward(40) .PHP_EOL;

PHP 引数

 <?php

function showAd($message = ‘Ad’) //仮引数

{

  echo ‘———-‘ . PHP_EOL;

  echo ‘— ‘ . $message . ‘ —‘ . PHP_EOL;

  echo ‘———-‘ . PHP_EOL;

}

showAd(‘Header Ad’); //実引数

echo ‘Tom is great!’ . PHP_EOL;

echo ‘Bob is great!’ . PHP_EOL;

// showAd(‘Ad’);

showAd();

echo ‘Steve is great!’ . PHP_EOL;

echo ‘Bob is great!’ . PHP_EOL;

showAd(‘Footer Ad’);

MSB8020 v142 (プラットフォーム ツールセット = ‘v142’) のビルド ツールが見つかりません。

 https://scrapbox.io/gosyujin/MSB8020_v142_(%E3%83%97%E3%83%A9%E3%83%83%E3%83%88%E3%83%95%E3%82%A9%E3%83%BC%E3%83%A0_%E3%83%84%E3%83%BC%E3%83%AB%E3%82%BB%E3%83%83%E3%83%88_=_’v142′)_%E3%81%AE%E3%83%93%E3%83%AB%E3%83%89_%E3%83%84%E3%83%BC%E3%83%AB%E3%81%8C%E8%A6%8B%E3%81%A4%E3%81%8B%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%80%82