[lang-ref] 文字列中の数式補完 ( php )

<?php
public function testStringInterpolationWithExpressionAlternative(): void
{
	// sprintf(...), concatenation, etc.
	$age = 20;
	$s = 'I am ' . ($age - 2) . ' years old.';
	$this->assertSame('I am 18 years old.', $s);
}