数据类型和对象之间的区别

I am new to JAVA and would like to ask what is the difference between data type and object. To be specific, I would like to ask what is the difference between data type (float) and object (Float) ? What is the advantage of using object Float, instead of type float? Can you give me some examples?

我是JAVA的新手,想问一下数据类型和对象有什么区别。具体来说,我想问一下数据类型(float)和object(Float)有什么区别?使用对象Float的优点是什么,而不是float类型?你能举个例子吗?

In addition, what is the advantage of using type float, instead of object Float?

另外,使用float类型而不是对象Float有什么好处?

Moreover, can I store multiple float values into object Float?

此外,我可以将多个浮点值存储到对象Float中吗?

1 个解决方案

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Float is a wrapper class. Wrapper classes are generally used to represent a primitive type (In Java primitive types are byte, int, float, etc.) when an Object is required. All of the wrapper classes inherit from the Number class.

Float是一个包装类。当需要Object时,包装类通常用于表示基本类型(在Java原始类型中是byte,int,float等)。所有包装类都继承自Number类。

The advantage of using a wrapper object like Float is that in some cases you will be able to use Float where you couldn't use float. For instance Lists such as an ArrayList can only hold reference types (i.e. objects, not primitives).

使用像Float这样的包装器对象的优点是,在某些情况下,您可以在不能使用float的情况下使用Float。例如,诸如ArrayList之类的列表只能保存引用类型(即对象,而不是基元)。

You can go:

你可以走了:

ArrayList<Float>....

but using

ArrayList<float>....

won't work and will result in a syntax error.

将无法正常工作,并将导致语法错误。

Oracle has a tutorial on this

Oracle有一个关于此的教程

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