程序如下：
import java.io.*;
public class practise
{
public static void main(String[] args)
{
/*
practise prc=new practise();
practise prc1=new practise();
System.out.println(prc.hashCode());
System.out.println(prc1.hashCode());
*/
DataInputStream in=new DataInputStream(System.in);
DataOutputStream out=new DataOutputStream(System.out);
try
{
System.out.print("请输入整数："); int a=in.readInt(); //为什么需要输入多次,只能够读四个字节？
System.out.print("请输入浮点数：");
double b=in.readDouble(); in.close();
out.writeInt(a);
out.writeDouble(b);
out.close(); //close会隐含地调用flush函数
}
catch (IOException e)
{
e.printStackTrace();
}
}
}我的问题是：为什么输入的时候有时候遇到问题，例如不止一次输入。
eg input:
4
4
4
4eg ouput:
4
4
4
4我明明只要输入一个整数一个符点数，为什么需要输入四次，而且都正确地读出来了呢？
哪位高手能够解决这个问题~~~~谢谢了~~~
import java.io.*;
public class practise
{
public static void main(String[] args)
{
/*
practise prc=new practise();
practise prc1=new practise();
System.out.println(prc.hashCode());
System.out.println(prc1.hashCode());
*/
DataInputStream in=new DataInputStream(System.in);
DataOutputStream out=new DataOutputStream(System.out);
try
{
System.out.print("请输入整数："); int a=in.readInt(); //为什么需要输入多次,只能够读四个字节？
System.out.print("请输入浮点数：");
double b=in.readDouble(); in.close();
out.writeInt(a);
out.writeDouble(b);
out.close(); //close会隐含地调用flush函数
}
catch (IOException e)
{
e.printStackTrace();
}
}
}我的问题是：为什么输入的时候有时候遇到问题，例如不止一次输入。
eg input:
4
4
4
4eg ouput:
4
4
4
4我明明只要输入一个整数一个符点数，为什么需要输入四次，而且都正确地读出来了呢？
哪位高手能够解决这个问题~~~~谢谢了~~~
/**
* See the general contract of the <code>readInt</code>
* method of <code>DataInput</code>.
* <p>
* Bytes
* for this operation are read from the contained
* input stream.
*
* @return the next four bytes of this input stream, interpreted as an
* <code>int</code>. //看看这里，返回四个byte，所以你要输入四个数据
* @exception EOFException if this input stream reaches the end before
* reading four bytes.
* @exception IOException if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
public final int readInt() throws IOException
/**
* See the general contract of the <code>readDouble</code>
* method of <code>DataInput</code>.
* <p>
* Bytes
* for this operation are read from the contained
* input stream.
*
* @return the next eight bytes of this input stream, interpreted as a
* <code>double</code>. //看看这里，返回把8个byte
* @exception EOFException if this input stream reaches the end before
* reading eight bytes.
* @exception IOException if an I/O error occurs.
* @see java.io.DataInputStream#readLong()
* @see java.lang.Double#longBitsToDouble(long)
*/
public final double readDouble() throws IOException
int是2位长度
double是4位长度
要求输入足够长度
double要读入8个字符
记得算上\n
int num = input.nextInt();