Java开发网 - 请教 (char c 没初始化)

Topic: 请教 (char c 没初始化)

1.请教 (char c 没初始化)	Copy to clipboard
Posted by: 雪原 Posted on: 2004-10-13 20:49 import java.io.*; public class xiao { public static void main(String args[]) {char c; System.out.println(" 请输入"); try{ c=(char)System.in.read(); } catch(IOException e){} System.out.println(" 输入"+c);} } 运行时系统提示为 c 好象没初始化为什么啊请问如何改进啊 { 请尽量用准确的文字描述作为标题 }

2.Re:请教 (char c 没初始化) [Re: 雪原]

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Posted by: why
Posted on: 2004-10-13 21:02


import java.io.*;

public class Xiao { 
  public static void main(String args[]) {
    char c;  // c 没初始化
    System.out.println(" 请输入");

    try {
      c=(char)System.in.read();  
    } catch(IOException e) { // if there's an exception, c 没初始化 }

    System.out.println(" 输入"+c);
  }
}

3.Re:请教 (char c 没初始化) [Re: 雪原]	Copy to clipboard
Posted by: qingbo777 Posted on: 2004-10-13 21:09 版主还真是耐心啊

4.Re:请教 [Re: 雪原]	Copy to clipboard
Posted by: archonLing Posted on: 2004-10-13 21:12 You need to initialize the "char c" for System.out.println(" 输入"+c);} to work. ex: char c = ' ';

5.Re:请教 (char c 没初始化) [Re: qingbo777]	Copy to clipboard
Posted by: helloworld Posted on: 2004-10-13 21:38 or : try{ char c = (char) ......

6.Re:请教 (char c 没初始化) [Re: 雪原]	Copy to clipboard
Posted by: zxhhero Posted on: 2004-10-13 22:33 楼上的大哥能说一下那样改的理由吗？

7.Re:请教 (char c 没初始化) [Re: helloworld]	Copy to clipboard
Posted by: archonLing Posted on: 2004-10-13 23:09 helloworld wrote: or : try{ char c = (char) ...... This will not work. Variable declared inside the try block may not be visible to the Exception clause. char c has to be initialized outside.

8.Re:请教 (char c 没初始化) [Re: 雪原]	Copy to clipboard
Posted by: lvqiang Posted on: 2004-10-14 00:33 在try{}catch(){}外定义的c在其中是无用的。只要改成这样就好了！ import java.io.*; public class xiao{ public static void main(String args[]){ System.out.println(" 请输入"); try{ char c =(char)System.in.read(); System.out.println(" 输入"+c); } catch(IOException e){} } }

9.Re:请教 (char c 没初始化) [Re: 雪原]	Copy to clipboard
Posted by: HW升 Posted on: 2004-10-14 13:32 楼上的仁兄是对的！

10.Re:请教 (char c 没初始化) [Re: 雪原]	Copy to clipboard
Posted by: 雪原 Posted on: 2004-10-15 18:53 谢谢楼住和各位没办法刚开始学啊呵呵