PHP延迟字符串插值

Question

有没有办法'准备'字符串以便以后插值(不使用自定义扩展功能)？
例如:

class Test {
    private static $STR_VAL = "the val is $v";

    public static function printVal($v) {
        echo self::$STR_VAL;
    }
}

Answer 1

sprintf()

class Test {
    private static $STR_VAL = "the val is %s";

    public static function printVal($v) {
        echo sprintf(self::$STR_VAL, $v);
    }
}