java控制台输入 [英] java console input

问题描述

通过控制台输入的任何数据类型（就像我使用BufferedReader类一样）是String.After之后我们输入它来重新排列数据类型（作为整数的Inter.parseInt（））。但是在C中我们可以采取任何原始数据类型的输入，而在java中，所有输入类型都是String.why它是如此????

The data type of the any input through console (as i do using BufferedReader class) is String.After that we type cast it to requered data type(as Inter.parseInt() for integer).But in C we can take input of any primitive data type whereas in java all input types are neccerily String.why it is so????

推荐答案

控制台输入实际上是作为一系列字节读入的，而不是字符串。这是因为API将 System.in 公开为 InputStream 。在JDK1.5之前的典型包装（对于 Scanner 类来说很好！）类似于：

Console input is actually read in as a series of bytes, not a String. This is because System.in is exposed by the API as an InputStream. The typical wrapping before JDK1.5 (hooray for the Scanner class!) was something like:

BufferedReader in = new BufferedReader（new InputStreamReader（System.in））;

ie InputStreamReader 将字节流转换为字符流，然后 BufferedReader 用于执行 readLine（）操作，或者其他什么。

i.e. InputStreamReader converts the byte stream into a character stream and then the BufferedReader is used to do your readLine() operations, or whatever.

所以这是一个 String 输出，因为你'从 BufferedReader 获取字符流的缓冲输出。

So it's a String output because you're getting the buffered output of a character stream from your BufferedReader.

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