help me with this minor mistake

[Erjan Kenjegalee]

hi everyone, i am novice here))))

    import java.util.*;
public class Operations_with_Array {
	public static void main(String args []){
long[] long_array2 = {-100,100,6,3 ,2 ,9 } ;

public static int sum_only2(long []x){
		int sum = 0 ;
		for(int counter = 0 ; counter < x.length ;counter++){
			sum+=x[counter] ;
		}
		return sum;	
	}
	
public void theAverage(long[]y){
		
		System.out.println(  (sum_only2(long[]y) )/y.length);
	} 

the thing is that Eclipse gives me a mistake in theAverage method - it underlines long[] y - i don't know why!
"syntax error misplaced constructs"

any suggestions?

[Henry Wong]

I am assuming that it is at line 16? When you call a method, you don't need to declare the type of the variable that you are passing -- the compiler knows what it is.

Henry

[Erjan Kenjegalee]

thanks Henry!
it works ok now.

i also have one more question

why should i declare the method theAverage static?

it looks like all methods outside of static main method

must be declared static ? right?
can you explain it to me?

[Nicola Garofalo]

You should not declare your method static unless you are invoking it directly in a static context.
If you want to invoke it directly in main method (a static method), you must declare it as static

Look at the following use:

...
public static void main(String args []){
  long[] long_array2 = {-100,100,6,3 ,2 ,9 } ;   
  theAverage(long_array2);
}
...

In the snippet of code your method theAverge has to be static, because i am invoking it inside a static method (the main method) directly.

But look at this:

...
public static void main(String args []){
  long[] long_array2 = {-100,100,6,3 ,2 ,9 } ;   
  Operations_with_Array op = new Operations_with_Array();
  op.theAverage(long_array2);
}
...

now you create an object of class Operations_with_Array and you invoke the method theAverage on that object.
The method now is an instance method, not a static method.