你没有实例化你的对象!
public class FindLaws{
public FindLaws(){}
public int getNum(int i) {
//
}
public static void main(String[] args){
FindLaws fl=new FindLaws();
//.............fl.getNum()
}
}
public class FindLaws{
public FindLaws(){}
public int getNum(int i) {
//
}
public static void main(String[] args){
FindLaws fl=new FindLaws();
//.............fl.getNum()
}
}
解决方案 »
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int str;
str = i * i;
if (str >= 10) {
str = str / 10 + str % 10;
}
if (str >= 10) {
str = str / 10 + str % 10;
}
return str;
}
public static void main(String[] args){
FindLaws fl=new FindLaws();
for (int i = 1; i < 10; i++) {
String lineStr = "";
int l1=0,l2=0,l3=0,l4=0;
l1 = i;
l2 = fl.getNum(l1);
l3 = fl.getNum(l2);
l4 = fl.getNum(l3);
lineStr =String.valueOf(l1) + ":" +
String.valueOf(l1) + " " +
String.valueOf(l2) + " " +
String.valueOf(l3) + " " +
String.valueOf(l4);
System.out.println(lineStr);
}
}
}这样搞定了!
我现在就是想把整个程序都写在main中,就象我的原程序一样
怎么会出现那样的错误呢
我只是想把原程序修改好
(不过,这个程序也有点小问题,大家顺便帮我解决一下,没分了,没办法)import java.io.*;public class Average{
public static void main( String args[ ] ) throws IOException
{
int counter, grade, total, average;
total=0;
counter=1;
while( counter <=10 ){
System.out.print("Enter letter grade: " );
System.out.flush();
grade = System.in.read( );
if( grade=='A' )
total = total+4;
else if(grade == 'B' )
total = total+3;
else if(grade == 'C' )
total = total+2;
else if(grade == 'D' )
total = total+1;
else if(grade == 'F' )
total = total+0;
System.in.skip( 1 );
counter = counter + 1;
}
average = total/10;
System.out.println( "Class average is "+average );
}
}
public int getNum(int i) {
int str;
str = i * i;
if (str >= 10) {
str = str / 10 + str % 10;
}
if (str >= 10) {
str = str / 10 + str % 10;
}
return str;
}
public static void main(String[] args){
FindLaws FL = new FindLaws();
for (int i = 1; i < 10; i++) {
String lineStr = "";
int l1,l2,l3,l4;
l1 = i;
l2 = FL.getNum(l1);
l3 = FL.getNum(l2);
l4 = FL.getNum(l3);
lineStr =String.valueOf(l1) + ":" +
String.valueOf(l1) + " " +
String.valueOf(l2) + " " +
String.valueOf(l3) + " " +
String.valueOf(l4);
System.out.println(lineStr);
}
}
}
写在main外面,然后建立对象就可以了。
A 4分
B 3
C 2
D 1
F 0
输入十个字母,算出平均分
那个程序是书上的,编译的时候没问题,但运行时出错,但也不知道为什么错啦
total = total+4;
else if(grade == 'B' )
total = total+3;
else if(grade == 'C' )
total = total+2;
else if(grade == 'D' )
total = total+1;
else if(grade == 'F' )
total = total+0;
==> 可以改成total += 'F' - grade;
java后输入第一个数据回车后出错如下:
D:\Java>java Average
Enter letter grade: A
Enter letter grade: Exception in thread "main" java.io.IOException: 句柄无效。
at java.io.FileInputStream.skip(Native Method)
at java.io.BufferedInputStream.skip(Unknown Source)
at Average.main(Average.java:32)请问这是怎么回事???多谢啦