它习惯上完成一个调用来确定：你需要分配多大的一个缓冲区，第二个调用取得数据，类似下面。

It's customary to make one call to find out how big a buffer you need to allocate and a second call to get the data, as follows.

youdao

试试下面的建议，这能帮你计算出你的技能和经验对于潜在雇主来说有多大价值。

Use this advice to figure out what your skills and experience are worth to a potential employer.

youdao