php - 二重引用符内で算術演算を実行できますか?

Question

文字列の引用符内で $x+$y のような算術演算を実行できないでしょうか?

// Expected result is:
// 5 + 11 = 16
echo "$x + $y = {$x+$y}"; // Parse error
echo "$x + $y = {$x}+{$y}"; // 5 + 11 = 5+11
echo "$x + $y = ${x+y}"; // 5 + 11 =

Answer 1

I wonder if we can do some arithmetic operation, like $x+$y, within a string quote?

Yes you can. You can just let PHP caclulate the arithmetric operation and then assign it to a variable and output it.

You can also do that inside a double-quoted string (Demo):

<?php
// @link http://stackoverflow.com/a/18182233/367456
//
// Expected result is:
// 5 + 11 = 16

$x = 5;
$y = 11;

echo "$x + $y = ${0*${0}=$x + $y}"; # prints "5 + 11 = 16"

However that is probably not what you're looking for.

Answer 2

このようにする必要があります。以下の行を

echo "$x + $y = {$x}+{$y}"; // 5 + 11 = 5+11

に

echo "$x + $y = ".($x+$y); // 5 + 11 = 16

Answer 3

以下のコードを試してください：

<?php
    $x =5;
    $y =11;
echo "$x + $y = ".($x+$y);
?>

また、このフィドルを参照してください

Answer 4

echo "$x + $y = ".($x+$y);

あなたはこのようにするかもしれません。

Answer 5

次の形式を使用し、好きでなければなりません

                $a=10;$b=12;
                 echo "$a+$b"."=".($a+$b);