NullPointerException

Return empty string when argument is null

Report a typo

Take a look at the method that takes a string, converts all characters of the string to upper case, and then returns the resulting string.

But there is a problem. Sometimes an input string is null. As you already know, in this case, the method throws a NullPointerException.

Your task is to fix the method in order to avoid an NPE.

If the input string is null, the method should return the empty string "".

Sample Input 1:

a string

Sample Output 1:

A STRING

Write a program in Java 17

import java.util.Scanner;

import java.util.Locale;

public class Main {

/* Fix this method */

public static String toUpperCase(String str) {

return str.toUpperCase(Locale.ENGLISH);

}

/* Do not change code below */

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

String line = scanner.nextLine();

line = "none".equalsIgnoreCase(line) ? null : line;

System.out.println(toUpperCase(line));

}

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