If you want to maintain a single instance of a variable for all instances of a class, you will use static-class member variables to do it.

如果您想为一个类的所有实例维持一个变量的实例，将会用到静态类成员变量。

youdao

I've made the number a member variable within the Classifier2 class, which allows me to avoid passing it around as a parameter to a bunch of static methods.

我把数字变成是Classifier 2类中的成员变量，这将允许我避免将其作为参数传递给一大堆静态方法。

youdao

This is a static member that is invoked directly without creating an instance of its class.

这是静态的成员，可以直接叫用而不需要建立其类别的执行个体。

youdao