.class error during declaring/initializing variables?

Question

I'm in the process of learning java. Today, my task was to find the errors in some code. I'm in the process of working on it, but I have no idea why the following error occurs. In the sample code, it gives me a ".class expected" on the line "int momsAge= 42; dadsAge= 43;" specifically, it puts an error line right infront of momsAge.

// A class that computes the sample statistics of the ages of
// family members.
public class FamilyStats
{
public static void main(String[] args)
{
/*
math equations obtained from: */
http://mathworld.wolfram.com/SampleVariance.html

// define some ages

int momsAge= 42; dadsAge= 43;
int myAge= 22, sistersAge= 16;
int dogsAge= 6;

// get the mean

double ageSum = (momsAge + dadsAge + myAge + sistersAge + DogsAge);
double average = ageSum / 5

/ calculate the sample variance
double variance= 0.0;
variance += (momsAge - average)*(momsAge - average);
variance += (dadsAge - average)(dadsAge - average);
variance += (myAge - average)*(myAge - average);
variance += (sistersAge - average)*(sistersAge - average);
variance += (dogsAge - average)*(dogsAge - average);
variance = variance / 4;

// get the std. dev
double standardDev= Math.sqrt(variance);
// output the results
System.out.println("The sample age mean is: " + average);
System.out.println("The sample age variance is: " + variance);
System.out.println("The sample age standard deviation is: " + standardDev);
}
}

Jeroen Vannevel · Accepted Answer · 2013-09-15 15:54:15Z

4

int momsAge= 42; dadsAge= 43;

should be

int momsAge= 42, dadsAge= 43;

The ; serves as the end of the statement, thus essentially making your next statement

dadsAge = 43;

Obviously this is wrong because a class is expected. Using the , allows you to chain those assignments.

Also:

http://mathworld.wolfram.com/SampleVariance.html

isn't commented (at least the http: part isn't).

edited Sep 15, 2013 at 15:54

answered Sep 15, 2013 at 15:31

Jeroen Vannevel

44.6k25 gold badges114 silver badges174 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

A4L Over a year ago

or insert another int after the semicolon -> int momsAge= 42; int dadsAge= 43;

Sloan Keychain Over a year ago

So, I went back and changed that (thanks), but it is still giving me a .class expected error, in the same place.

StepTNT · Accepted Answer · 2013-09-15 16:02:54Z

Here's the correct code with the inline corrections that I made:

// A class that computes the sample statistics of the ages of
// family members.
public class FamilyStats {

    public static void main(String[] args) {
        /*
         math equations obtained from: 
         http://mathworld.wolfram.com/SampleVariance.html
         */ 
       //^--Included the url into the comments
// define some ages
        int momsAge = 42, dadsAge = 43;
                      //^--Changed ; to ,
        int myAge = 22, sistersAge = 16;
        int dogsAge = 6;

// get the mean

        double ageSum = (momsAge + dadsAge + myAge + sistersAge + dogsAge);
        double average = ageSum / 5;
        // calculate the sample variance
       //^--Added the second / to mark the line as a comment
        double variance = 0.0;
        variance += (momsAge - average) * (momsAge - average);
        variance += (dadsAge - average) * (dadsAge - average);
        variance += (myAge - average) * (myAge - average);
                                    //^--Added missing * symbol
        variance += (sistersAge - average) * (sistersAge - average);
        variance += (dogsAge - average) * (dogsAge - average);
        variance = variance / 4;

// get the std. dev
        double standardDev = Math.sqrt(variance);
// output the results
        System.out.println("The sample age mean is: " + average);
        System.out.println("The sample age variance is: " + variance);
        System.out.println("The sample age standard deviation is: " + standardDev);
    }
}

Collectives™ on Stack Overflow

.class error during declaring/initializing variables?

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related