java.lang.NoClassDefFound error

[swathi dharmaraj]

[B][B]a program to calculate avg of students:
import java.util.*;
import java.io.*;
public class student1
{
public static void main(String a[]) throws IOException
{
int m1,m2,m3,m4,sum,avg;
try
{
DataInputStream g=new DataInputStream(System.in);
m1=Integer.parseInt(g.readLine());
m2=Integer.parseInt(g.readLine());
m3=Integer.parseInt(g.readLine());
m4=Integer.parseInt(g.readLine());
System.out.println("enter the marks of 4 subjects");
avg=g.display(m1,m2,m3,m4);
System.out.println("result is:"+avg);
}
catch(Exception e)
{
System.out.println("error");
}
}
}
class display1
{
public double display(int mk1,int mk2,int mk3,int mk4)
{
double avrg;
avrg=(mk1+mk2+mk3+mk4)/4;
return avrg;
}
}
the error is as follows pls help:confused:
student1.java:17: cannot find symbol
symbol : method display(int,int,int,int)
location: class student1
avg=stud.display(m1,m2,m3,m4);
^
Note: student1.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error

[JosAH]

The code you have shown us is not the code you tried to compile or you have made up the compiler error message. Don't try to fool us and be exact about what's causing you problems.

kind regards,

Jos

[swathi dharmaraj]

sorry for the trouble..
here is the code

import java.io.*;
public class student1
{
public static void main(String a[]) throws IOException
{
int m1,m2,m3,m4,sum,avg;
student1 stud=new student1();
try
{
DataInputStream g=new DataInputStream(System.in);
m1=Integer.parseInt(g.readLine());
m2=Integer.parseInt(g.readLine());
m3=Integer.parseInt(g.readLine());
m4=Integer.parseInt(g.readLine());
System.out.println("enter the marks of 4 subjects");
stud.display(m1,m2,m3,m4);
}
catch(Exception e)
{
System.out.println("error");
}
}
private void display(int m1, int m2, int m3, int m4)
{
int avrg;
avrg=(m1+m2+m3+m4)/4;
System.out.println("result is:"+avrg);
}
}

the error msg:


C:\Users\swathi>path C:\Program Files (x86)\Java\jdk1.6.0_03\bin

C:\Users\swathi>javac student1.java
Note: student1.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

C:\Users\swathi>java student1.java
Exception in thread "main" java.lang.NoClassDefFoundError: student1/java

[UJJAL DHAR]

You are working on main() method. In netbeans there is no compilation error.But may be some bugs in your code.
Did you save your source code name as student1.java?

student1 stud=new student1();

Where is your constructor?There is no need of this line I think.

Be confident about this lines

DataInputStream g=new DataInputStream(System.in);
m1=Integer.parseInt(g.readLine());
m2=Integer.parseInt(g.readLine());
m3=Integer.parseInt(g.readLine());
m4=Integer.parseInt(g.readLine());
System.out.println("enter the marks of 4 subjects");
stud.display(m1,m2,m3,m4);

You can use Scanner class for taking inputs from keyboard.

Regards
Ujjal

[swathi dharmaraj]

please guide on creating objects and using them to invoke functions within the same class and outside with example code.

[swathi dharmaraj]

yes i did save the file as student1.java

[UJJAL DHAR]

//student1.java///

class classname1{

public classname1(){  
 //write your code here constructor
}


};


public class student1{
public static void main(String a[]){
//create instances here

classname1 object=new classname1();
} 

}

Why I am writing this code here? I think you already know this...

[ra4king]

There is nothing wrong with your code.
The error is in how you type it in the command line:

javac Student1.java
//compiles file
java Student1
//runs program

You do not add ".java" at the end of the class name when running it.

[to_devendra]

this is wrong
avg=g.display(m1,m2,m3,m4);
that should be as below

display1 dis=new display1();
avg=dis.display(m1,m2,m3,m4);

int avg
should be
double avg;

now , your code will work...

[ra4king]

@to_devendra
we have already clarified that. please read earlier comments before posting anything next time.

[swathi dharmaraj]

thanks a lot :)

[ra4king]

Glad to help :D