什么是一个打印的字符数组的输出是什么意思？ [英] What does the output of a printed character array mean?

问题描述

我从C现在转向Java和我以下有关弦乐一些教程。在教程一个点，他们从显示的字符数组初始化一个新的字符串，然后打印字符串。我正沿着以下，但我想同时打印字符数组和字符串所以我想这样的：

 类无论{
    公共静态无效的主要（字符串ARGS []）{
        的char []你好= {'H'，'E'，'L'，'L'，'O'，'。'};
        字符串串hello_str =新的String（你好）;
        的System.out.println（你好++串hello_str）;
    }
}
 

我的产量是这样的：

  [C @ 9304b1打招呼。
 

显然，这是不是你将如何打印在Java中的字符数组。但是我不知道是否我刚刚得到的垃圾？我看了一些网站，打印字符数组给你一个地址，但是，这并不像一个地址给我...我还没有发现在网上有很多关于它的。

所以，我怎么只打印？
结果和奖金的问题：
你如何正确地在Java打印的字符数组？

解决方案

  

但我不知道是否我刚刚得到的垃圾？

没有，你得到的 Object.toString（） ，这是不是在阵列覆盖：

  

Object类的toString方法返回一个包含其中的对象是一个实例，该符号字符'@'的类名称的字符串，散列$ C的无符号十六进制再presentation对象$ C。换句话说，该方法返回字符串等于的值：

 的getClass（）。的getName（）+'@'+ Integer.toHexString（哈希code（））
 

所以它不是的垃圾的，因为它有一个意思......但它不是一个特别的有用的价值，无论是。

和您的奖金的问题...

  

你如何正确地在Java打印的字符数组？

呼叫的 Arrays.toString（的char []） 将其转换为字符串...或只是

 的System.out.println（你好）;
 

这将调用的println（的char []）来代替，将其转换成字符串。需要注意的是 Arrays.toString 将建立一个字符串，这显然是一个字符数组，而的System.out.println（你好）大致等同于的System.out.println（新的String（你好））

I'm moving from C to Java now and I was following some tutorials regarding Strings. At one point in the tutorials they showed instantiating a new string from a character array then printing the string. I was following along, but I wanted to print both the character array and the string so I tried this:

class Whatever {
    public static void main(String args[]) {
        char[] hello = { 'h', 'e', 'l', 'l', 'o', '.'};
        String hello_str = new String(hello);
        System.out.println(hello + " " + hello_str);
    }
}

My output was something like this:

[C@9304b1 hello.

Clearly, this is not how you would print a character array in Java. However I'm wondering if I just got garbage? I read on some site that printing a character array give you an address, but that doesn't look like an address to me... I haven't found a lot online about it.

So, what did I just print?
and bonus questions: How do you correctly print a character array in java?

解决方案

However I'm wondering if I just got garbage?

No, you got the result of Object.toString(), which isn't overridden in arrays:

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

getClass().getName() + '@' + Integer.toHexString(hashCode())

So it's not garbage, in that it has a meaning... but it's not a particularly useful value, either.

And your bonus question...

How do you correctly print a character array in java?

Call Arrays.toString(char[]) to convert it to a string... or just

System.out.println(hello);

which will call println(char[]) instead, which converts it into a string. Note that Arrays.toString will build a string which is obviously an array of characters, whereas System.out.println(hello) is broadly equivalent to System.out.println(new String(hello))

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