在被单引号(即省略号，呼号)环绕的文本字面值里，变量替换不会进行。

Variable substitution is not done in text literals which are surrounded by single quotes (apostrophe s).

youdao

在被单引号(即省略号，呼号)环绕的文本字面值里，变量替换不会进行。

Variable substitution is not done in text literals which are surrounded by single quotes (apostrophe s).

youdao