Array(配列)

<?php
$array = array(
    "foo" => "bar",
    "bar" => "foo",
);

// 配列の短縮構文
$array = [
    "foo" => "bar",
    "bar" => "foo",
];
?>

<?php
// 配列宣言
$arr1 = array(
    "KEY1" => "11111",
    "KEY2" => "222",
    "KEY3" => "3333",
    "KEY4" => "44444",
    0      => 100,       // キー：数値!!
    "KEY5" => "555",
);
 
echo "<pre>";
print_r($arr1);
echo "</pre>";

// 配列の内容を順次取得する「foreach」を使ってループ処理
foreach($arr1 as $key => $value) {
    echo "\$arr1[".$key."]=".$value."<br />\n";
?>

<?php
// 要素が数値のみの配列
$arr1 = array(10, 20, 30);
// 配列の内容を順次取得する「foreach」を使って反復処理
foreach($arr1 as $i => $value) {
    echo "\$arr1[".$i."]=".$value."<br />\n";

// 「foreach」で指標の取得無し
foreach($arr1 as $value) {
    echo "DATA=".$value."<br />\n";

}
?>

<?php
$array = array(
    "foo" => "bar",
    "bar" => "foo",
    100   => -100,
    -100  => 100,
);
var_dump($array);
?>

<?php
$array = array(
         "a",
         "b",
    6 => "c",
         "d",
);
var_dump($array);
?>

<?php
$array = array(
    "foo" => "bar",
    42    => 24,
    "multi" => array(
         "dimensional" => array(
             "array" => "foo"
         )
    )
);

var_dump($array["foo"]);
var_dump($array[42]);
var_dump($array["multi"]["dimensional"]["array"]);
?>