以上代码首先检查是否存在实例。

The code first checks to see if there are any instances.

youdao

在这之后强盗们首先检查了这个洞。

The first care of the robbers after this was to examine the cave.

youdao

可以看到，首先检查更改了哪个属性。

As you can see, you first check which property has changed.

youdao

First of all, having read in that value, I can check to see, is it of the right type?

首先，读一下这个值，我们可以来检查看看是不是正确的类型？

麻省理工公开课 - 计算机科学及编程导论课程节选

First, I'm going to do a sanity check strlen so we've used string length, strlen, before.

首先，我先做一个检查,我们以前使用过字符串长度函数。

哈佛公开课 - 计算机科学课程节选

Check first is N less than 2.

首先检查N是否小于。

哈佛公开课 - 计算机科学课程节选