Can't run the code in command line

[Istvan Müller]

Hi
So I've recently started using Java for a school project. One part of this project is a calculator to calculate the average of a certain amout of marks. I've obviously gotten a few errors the first few times when I tried to run the program, however, after I fixed the errors, the comand prompt just didn't run the code and reset to the standart directory view (C:\Users\MyUsername\Desktop>). There are no errors displayed but since the code should have an output it didn't work. I would appreciate it, if anyone could help me either fix this or recommend another program (expect comand prompt) which helps me see whether the code is working or not.
Thanks a lot.
-Me

[Liutauras Vilda]

A warm welcome to the Ranch

When posting code, is always better/preferred to post an actual code rather than its picture. So please do.

Could you please tell us:
1. What inputs you have passed
2. What was the expected output
3. What was an actual output

[Liutauras Vilda]

As a suggestion how better is to structure you program.

Try to obtain inputs and add them to some kind of data structure. For instance: an array or list. Once you have it, you can create a method which calculates average.

Example snippet:

...
int[] grades = {7, 9, 8, 8, 10};

double average = calculateAverage(grades);
...

double calculateAverage(int[] A) { // come up with a better name than 'A'
    // implement
    // return average
}

Also try to do similarly with taking input(s) from user. For which you could have something along the lines:

int[] grades = getNumbers(); 
// think maybe to pass a prompt text
// for example "Please enter the amount of exams you have had"

[Istvan Müller]

Liutauras Vilda wrote:A warm welcome to the Ranch

When posting code, is always better/preferred to post an actual code rather than its picture. So please do.

Could you please tell us:
1. What inputs you have passed
2. What was the expected output
3. What was an actual output

Thanks for your answer
I'm sorry, I was told not to post java code, so here it is in my reply.

import java.util.Scanner;

public class Calc { 

public static void main(String[] args) {
	float sum = 0; 
	float inputMark;
	int counter; 
	float avg; 
	Scanner MarkScanner = new Scanner(System.in); 
	
	System.out.println("Please enter the amount of exams you've had so far: ");
	
	counter = MarkScanner.nextInt();
	
	for(int i = 1; i <= counter; i ++); {
		inputMark = MarkScanner.nextInt(); 
		sum  = sum + inputMark;
		System.out.println();
	}
	
	avg = sum / counter; 
	System.out.println("Your grade average is " + avg);
}
}

As mentioned, I was not able to make any inputs, I attached another screenshot showing, what my comand prompt displays (my Username is censored bc it's cringe ). The first expected output should ask me to type in the amount of exams I've had so far.
Thanks for your Help
-Istvan

[Liutauras Vilda]

Please check line 16 carefully (up until '{').

[Istvan Müller]

I don't get it :3

[Liutauras Vilda]

Loop has no body due to semi-colon which finishes statement.

[Istvan Müller]

Ah I see, thanks for that. The comand prompt displays still the same tho .-.

[Liutauras Vilda]

So if you'd go back to my first post and answer questions, you might would figure out what the problem is (if there is any) after you removed uneccessary semi-colon.

[Istvan Müller]

Right

1. the only input I could pass to the comand prompt was "javac Calc.java"
2. the expected output was the sentence: "Please enter the amount of exams you've had so far: ". Since that's where I should get the value for the variable "counter".
3. I got no output out of the comand prompt, It just reset to the basic display, that I showed in the threat before with my screenshot.

I hope that's what you were asking for.

[Liutauras Vilda]

Well, yes and no

With 'javac Calc.java' you compile the program. What else you need to do, is to execute it with an instruction 'java Calc' so then you can interact with the program in the way you programmed it. Meaning you'd need to enter the amount of exams and then their corresponding grades received which would be used for the average calculation.

[Istvan Müller]

Damn, I see. we've been handling the wrong issue the whole time
I didn't run the program properly. What exactly do I have to type in the comand prompt to interact with the program? o.0 (sorry, it really is my first java code xD)

[Liutauras Vilda]

Istvan Müller wrote:What exactly do I have to type in

At this point I think is fair enough to say that you are expected to research yourself and try to figure out. You could find lots of information on Internet already which answers that type of question.

It is a bit weird that you have programming class and those type of things are covered in it.

[Istvan Müller]

Liutauras Vilda wrote:

Istvan Müller wrote:What exactly do I have to type in

At this point I think is fair enough to say that you are expected to research yourself and try to figure out. You could find lots of information on Internet already which answers that type of question.

It is a bit weird that you have programming class and those type of things are covered in it.

Thanks for your advice . I don't have programing classes in school to be fair, it's more like a free project where you can decide on your own, what you want to do. However thanks for you help again. <3

[Liutauras Vilda]

I, earlier wrote:you have programming class and those type of things are covered in it.

I meant aren't, not are.

Alright, I see. Then Oracle Java Tutorials might be the good resource for you to read and find some answers. Have a look here. So you could find some more structured and interim information about Java programming language. How to compile, how to execute, what is the class, etc...

[Istvan Müller]

Right, thanks for your help, again . I really appreciate your helpful and quick replies. I think this threat is finished and I will certainly try the tutorial you recommended.

[Liutauras Vilda]

No worries, you are welcome. Once you do some research, I'm sure you'll have some more concrete questions about the problem at hand how to approach it, and this is what we are mainly interested about instead of dry Q and A sessions.