CODEWITHSUNDEEP
java
shalini negi
shalini negi

Reputation: 23

how to fix " illegal start of expression" error while declare method in java

I have declared a simple method inside a class that checks if a number is triangular or not but while declaring the method the compiler shows "illegal start of expression" error. Given Below is my code 

            import java.util.*;
            import java.lang.*;
            import java.io.*;
            class Ideone
            {
                public static void main (String[] args) throws java.lang.Exception
                {

                    int n ;
                    Scanner in = new Scanner (System.in) ;
                    n = in.nextInt() ;
                    static boolean  isTriagular ()
                    {
                        int tn = 1 ;
                        while ( n <= tn  )
                        {
                            if ( tn == n ) 
                            {
                                System.out.println("yes" ) ;
                                System.exit(0) ;
                            }
                            tn += ( tn + 1 ) ;
                        }
                    }
                    // your code goes here
                }
            }

Main.java:14: error: illegal start of expression static boolean isTriagular () ^

Upvotes: 0

Views: 100

Answers (2)

Ryan
Ryan

Reputation: 53

You should move isTriangular outside of your main method and then call your method in your main method as shown below:

import java.util.*;
import java.lang.*;
import java.io.*;

class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        int n ;
        Scanner in = new Scanner (System.in) ;
        n = in.nextInt() ;

        // your code goes here
        isTriagular();
    }

    static void isTriagular()
    {
        int tn = 1 ;
        while ( n <= tn  )
        {
            if ( tn == n ) 
            {
                System.out.println("yes" ) ;
                System.exit(0) ;
            }
            tn += ( tn + 1 ) ;
        }
    }
}

I changed the type of isTriangular to a void since you are exiting the entire program after printing something to the console. It would only need to be a boolean if you are returning a result from it to set equal to another variable.

An example of this is:

boolean myResult = isTriangular();

Upvotes: 1

Mouad Khali
Mouad Khali

Reputation: 124

you are declaring a function inside another function move isTriangulaire() declaration outside the main() function
you can call isTriangulaire() inside main after that

Upvotes: 0

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