DockerDesktopが起動しない場合の対処方法

https://engineer-ninaritai.com/docker-desktop-not-work/

PHP Fileに書き込み

PHP array_map()

$n * 1.1, $prices ); print_r($newPrices);

PHP 配列の連結

PHP array_splice()要素の削除置換

PHP 文字列と配列の相互の変換

PHP 文字列の検索、置換

PHP substr()､substr_replace()

PHP マルチバイト文字列

PHP 関数

PHP sprintf

PHP 変数の返り値

PHP 可変長引数

PHP 配列

 <?php

$moreScores = [

  55,

  72,

  'perfect',

  [90, 42, 88],

];

$scores = [

  90,

  40,

  ...$moreScores,

  100,

];

// print_r($scores);

echo $scores[5][2] . PHP_EOL;

PHP foreach

 <?php

$scores = [

  'first'  => 90, 

  'second' => 40, 

  'third'  => 100,

];

// foreach ($scores as $value) {

// foreach ($scores as $score) {

//   echo $score . PHP_EOL;

// }

foreach ($scores as $key => $score) {

  echo $key . ' - ' . $score . PHP_EOL;

}

PHP 配列

 <?php

$scores = [

  'first'  => 90, 

  'second' => 40, 

  'third'  => 100,

];

// var_dump($scores);

// print_r($scores);

echo $scores['third'] . PHP_EOL;

PHP 配列

 <?php

// $score1 = 90;

// $socre2 = 40;

// $score3 = 100;

$scores = [

  90,

  40,

  100,

];

$scores[1] = 60;

echo $scores[1] . PHP_EOL;

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 引数の型

 <?php

declare(strict_types=1);

function showInfo(string $name, int $score): void

{

  echo $name . ': ' . $score . PHP_EOL;

}

// showInfo('taguchi', 40);

// showInfo('taguchi', 'dotinstall');

showInfo('taguchi', '4');

PHP 条件演算子

 <?php

function sum($a, $b, $c) 

{

  $total = $a + $b + $c;

  

  // if($total < 0){

  //   return 0;

  // }else{

  //   return $total;

  // }

  return $total < 0 ? 0 : $total;

}

echo sum(100, 300, 500) .PHP_EOL; //900

echo sum(-1000, 300, 500) .PHP_EOL; //0