格式化字符串
此方法只是简单将指定占位符 按照顺序替换为参数
如果想输出占位符使用 \\转义即可,如果想输出占位符之前的 \ 使用双转义符 \\\\ 即可
例:
通常使用:format("this is {} for {}", "{}", "a", "b") =》 this is a for b
转义{}: format("this is \\{} for {}", "{}", "a", "b") =》 this is {} for a
转义\: format("this is \\\\{} for {}", "{}", "a", "b") =》 this is \a for b