"c" not 初期化, following is ok.import java.io.*; class simpleio { public static void main(String[] args) { char c; c = ' '; System.out.println("enter a letter:"); try{ c=(char)System.in.read(); } catch(IOException e){}; System.out.println("the letter is :"+c); } }
following is ok.import java.io.*;
class simpleio
{
public static void main(String[] args)
{
char c;
c = ' ';
System.out.println("enter a letter:");
try{
c=(char)System.in.read();
}
catch(IOException e){};
System.out.println("the letter is :"+c);
}
}
c=(char)System.in.read();因为这一句有可能有异常,所以报错。
import java.io.*;
class simpleio
{
public static void main(String[] args) throw IOException
{
char c;
System.out.println("enter a letter:");
try{
c=(char)System.in.read();
}
catch(IOException e){
throw e;
};
System.out.println("the letter is :"+c);
}
}
import java.io.*;
class simpleio
{
public static void main(String[] args) throws IOException
{
char c;
System.out.println("enter a letter:");
try{
c=(char)System.in.read();
}
catch(IOException e){
throw e;
};
System.out.println("the letter is :"+c);
}
}
class simpleio
{
public static void main(String[] args) throw IOException
{
char c = null;
System.out.println("enter a letter:");
try{
c=(char)System.in.read();
}
catch(IOException e){
throw e;
};
System.out.println("the letter is :"+c);
}
}
import java.io.*;
class simpleio
{
public static void main(String[] args)
{
char c;
System.out.println("enter a letter:");
try{
c=(char)System.in.read();
System.out.println("the letter is :"+c);
}
catch(IOException e){};
}
}
其实char是可以不初始化的!但你在打印输出之前得做!
你把System.out.println("the letter is :"+c);提到和赋值在一个模块里!就可以编译通过拉!
是用字符流类处理得!
import java.io.*;class BRRead{
public static void main(String arg[]) throws IOException {
char c;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter characters,'q' to quit."); //read characters
do{
c=(char)br.read();
System.out.println(c) ;
}while(c!='q'); } }
一定要在构造函数中付出值,否则不能进行任何操作
这点和C可是大大的不一样呀这个错误我也犯了好几次了
不过现在不会了