more than one public main main method in same package in java

Question

Can i have two or more public static void main(String args[]) method in **diffrent classes but same package **

I am new to java as well as stackoverflow.So sorry for any ignorance in advance.

I tried to put two classes with public static void main(String args[]) method in same package but on compiling one of the class there was an error "Could not find or load main class BinarySearch".

so my question is why can't we declare two main method in different classes when it is valid to declare other methods in different classes with same name??

code for first class

package geeksforgeeks;
class BinarySearch
{
// Returns index of x if it is present in arr[l..
// r], else return -1
int binarySearch(int arr[], int l, int r, int x)
{
    if (r>=l)
    {
        int mid = l + (r - l)/2;

        // If the element is present at the 
        // middle itself
        if (arr[mid] == x)
           return mid;

        // If element is smaller than mid, then 
        // it can only be present in left subarray
        if (arr[mid] > x)
           return binarySearch(arr, l, mid-1, x);

        // Else the element can only be present
        // in right subarray
        return binarySearch(arr, mid+1, r, x);
    }

    // We reach here when element is not present
    //  in array
    return -1;
}

// Driver method to test above
public static void main(String args[])
{
    BinarySearch ob = new BinarySearch();
    int arr[] = {2,3,4,10,40};
    int n = arr.length;
    int x = 10;
    int result = ob.binarySearch(arr,0,n-1,x);
    if (result == -1)
        System.out.println("Element not present");
    else
        System.out.println("Element found at index " + 
                                             result);
}
}

code for second class in same package

 package geeksforgeeks;

 import java.util.Scanner;

class LinearSearch{
  public static void main(String args[]){
  Scanner in = new Scanner(System.in);
  int [] a = new int[5];
  for(int i=0;i<5;i++)
    a[i]= in.nextInt();

   System.out.println("enter number to be found");
   int key = in.nextInt();

  for(int i=0;i<5;i++){
    if(a[i]==key){
    System.out.println("number is present");
    break;
  }
  if(i==4)
    System.out.println("number is not present");
}
 }
 }

and the terminal output is

C:\Users\ayush\Desktop\java\geeksforgeeks>javac BinarySearch.java

C:\Users\ayush\Desktop\java\geeksforgeeks>java BinarySearch
Error: Could not find or load main class BinarySearch

@user7 47 What is considered the entry point into the program if you have two? — Zebrafish, Mar 11 '18 at 06:28
@Zebrafish You can independently run those two classes having main methods — Thiyagu, Mar 11 '18 at 06:29
Enhance your question with your error and your for args. You are using to launch your app. — sn42, Mar 11 '18 at 06:31
@ayushaggarwal Provide code snippet and the errors you are getting by editing the question. — Jacob, Mar 11 '18 at 06:32
@user7 i tried to run one of the class with main method independently but during compilation it shows an error "Could not find or load main class" — Ayush Aggarwal, Mar 11 '18 at 06:32
@user7 sorry but that was not the problem. I have added code snippets and output of command prompt for more clarification. — Ayush Aggarwal, Mar 11 '18 at 06:58

score 3 · Accepted Answer · answered Mar 11 '18 at 07:03

3

The class BinarySearch is in package geeksforgeeks. To start it, your current directory needs to be c:\Users\ayush\Desktop\java and you must use the command line:

C:\Users\ayush\Desktop\java>java geeksforgeeks.BinarySearch

Alternatively, instead of changing the current directory, you can also specify the class path when you start it.

answered Mar 11 '18 at 07:03

Henry

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thanks that solved my problem. – Ayush Aggarwal Mar 11 '18 at 07:07
1

If this answer has solved your problem, please accept it so the person who answered it gets the points. Thanks. – Moose Morals Mar 11 '18 at 07:56

more than one public main main method in same package in java

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