菜鸟小问题

[skyboy0720]

import java.io.*;
public class IOTest
{
public static void main ( String [ ] args ) throws IOException
{
int b;
System.out.print ( "Input a integer:" );
int a = Integer.parseInt ( System.in.read ( ) );
System.out.println ( a + b );
}
}

这会出错,我就想从键盘获得一个整数,进行运算,很简单,怎么改,谢谢了

[希偌]

b???

[DainelLee]

import java.io.*;
public class IOTest
{
public static void main (String[] args )
{
int b = 4;
System.out.print ("Input a integer:");
int a;
char[] c = new char[1];
try {
a = System.in.read();
if ((a > 57) || (a< 48))
System.out.println("输入错误，请输入数字");
c[0] = (char)a;
System.out.println (" " + (Integer.parseInt(new String(c)) + b));
} catch (IOException e){
System.out.println("Error of IO");
}
}
}

我也才开始学java，不知哪位高手有更好的方法？

[jianlin]

System.in.read()的返回不是String型的

[LuZhou]

import java.io.*;
public class IOTest
{
public static void main ( String [ ] args )
{
int b;
System.out.print ( "Input a integer:" );
int a = Integer.parseInt ( System.in.read ( ) );
System.out.println ( a + b );
}
}

[seaman0916]

import java.io.*;
public class IOTest
{
public static void main ( String [ ] args ) throws IOException
{
int a=0,b=5; //要初始化的!
System.out.print ( "Input a integer:" );
try
{
a= Integer.parseInt( System.in.read( )); //这个可能会有异常抛出
}
catch(NumberFormationException e)
{
System.out.println("请确信输入的是数字!");
}
System.out.println ( a + b );
}
}

试试吧! 应该可以了

[kzjiang820218]

看了一下，但是不能帮你解决！

[seaman0916]

不好意思,上面写错了!

import java.io.*;
public class IOTest
{

public static String keyin()
{
String s=" ";
try
{
BufferedReader one=new BufferedReader(new InputStreamReader(System.in));
s=one.readLine();
}
catch(IOException e) {System.out.println("There was wrong !");}

return s;
}
public static void main ( String [ ] args ) throws IOException
{
int a=0,b=5; //要初始化的!
System.out.print ( "Input a integer:" );
try
{
a= Integer.parseInt(keyin( )); //这个可能会有异常抛出
}
catch(NumberFormationException e)
{
System.out.println("请确信输入的是数字!");
}
System.out.println ( a + b );
}
}


这下试试吧!刚才实在是不好意思! 忘记了!

[kzjiang820218]

非常谢谢 DainelLee(现在开始学java）
我又学到了东西！

[skyboy0720]

谢谢帮助,学到了东西!