php字串"符號帶變數用法

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<?php
$date = date("Y-m-d");
echo "$date之後要做什麼";

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<?php
// 顯示所有錯誤
error_reporting(E_ALL);

$great = 'fantastic';

// 無效，輸出: This is { fantastic}
echo "This is { $great}";

// 有效，輸出： This is fantastic
echo "This is {$great}";
echo "This is ${great}";

// 有效
echo "This square is {$square->width}00 centimeters broad."; 

$juices = array("apple", "orange", "koolaid1" => "purple");

echo "He drank some $juices[0] juice.".PHP_EOL;
echo "He drank some $juices[1] juice.".PHP_EOL;
echo "He drank some juice made of $juice[0]s.".PHP_EOL; // Won't work
echo "He drank some $juices[koolaid1] juice.".PHP_EOL;

class people {
    public $john = "John Smith";
    public $jane = "Jane Smith";
    public $robert = "Robert Paulsen";
    
    public $smith = "Smith";
}

$people = new people();

echo "$people->john drank some $juices[0] juice.".PHP_EOL;
echo "$people->john then said hello to $people->jane.".PHP_EOL;
echo "$people->john's wife greeted $people->robert.".PHP_EOL;
echo "$people->robert greeted the two $people->smiths."; // Won't work  多加s   害我一直再看哪裡有問題orz

/*
 * 
 * 下面特殊狀況
 * 
 */ 
 //有效
echo "This square is {$square->width}00 centimeters broad."; 

// 有效，只有通過花括號語法才能正確解析帶引號的鍵名
// 這個雷我可能還不知道

echo "This works: {$arr['key']}";

// 有效
echo "This works: {$arr[4][3]}";

//沒有帶key的字串可以不用{} ex:$arr[4][3]

// 這是錯誤的表達式，因為就像 $foo[bar] 的格式在字符串以外也是錯的一樣。
// 換句話說，只有在 PHP 能找到常量 foo 的前提下才會正常工作；這裡會產生一個
// E_NOTICE (undefined constant) 級別的錯誤。
echo "This is wrong: {$arr[foo][3]}"; 

// 有效，當在字符串中使用多重數組時，一定要用括號將它括起來
echo "This works: {$arr['foo'][3]}";

// 有效
echo "This works: " . $arr['foo'][3];

echo "This works too: {$obj->values[3]->name}";

/**
 * 下面很神奇，可以用function return 字串出來，但不能直接用function回傳字串
 * 感覺不是很實用...
 */

echo "This is the value of the var named $name: {${$name}}";

echo "This is the value of the var named by the return value of getName(): {${getName()}}";

echo "This is the value of the var named by the return value of \$object->getName(): {${$object->getName()}}";

// 無效，輸出： This is the return value of getName(): {getName()}
echo "This is the return value of getName(): {getName()}";

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<?php
// 顯示所有錯誤
error_reporting(E_ALL);

class beers {
    const softdrink = 'rootbeer';
    public static $ale = 'ipa';
}

$rootbeer = 'A & W';
$ipa = 'Alexander Keith\'s';

// 有效，輸出： I'd like an A & W
echo "I'd like an {${beers::softdrink}}\n";

// 也有效，輸出： I'd like an Alexander Keith's
echo "I'd like an {${beers::$ale}}\n";

?>

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<?php
$str = <<<'EOD'
Example of string
spanning multiple lines
using nowdoc syntax.
EOD;

/* 含有变量的更复杂的示例 */
class foo
{
    public $foo;
    public $bar;

    function foo()
    {
        $this->foo = 'Foo';
        $this->bar = array('Bar1', 'Bar2', 'Bar3');
    }
}

$foo = new foo();
$name = 'MyName';

echo <<<'EOT'
My name is "$name". I am printing some $foo->foo.
Now, I am printing some {$foo->bar[1]}.
This should not print a capital 'A': \x41
EOT;
?>