If an input is in the array return true, else false

The following code will return true if the array contains the input and false if it doesn't. Credits to camickr for this code:

Arrays.asList(yourArray).contains(yourString)

return false must be outside the for loop. If it's in the else part, the for loop will end at the first iteration.

Here's how the code should look like:

public boolean isIn(String input) {
    for(int i = 0; i < fruit.length; i++) {
        if (input.equals(fruit[i])) {
            return true;
        }
    }
    return false;
}

Also, you cannot declare a method inside another method. Move the method isIn outside main.

Other problems in your code:

• String[] fruit is currently declared, initialized and filled inside main method. It should be at least declared outside as a field of the class in order to be accessed by other methods.
• You're not using isIn anywhere.
• In order to use the fields and methods inside main method, you have two options:
  1. Declare the fields and methods as static.
  2. Create a new instance of your class inside the main method and use the fields and methods from this instance.

The code may look like this:

import java.util.Scanner;

public class StringArrayTest {
    static String[] fruit = new String[6];

    public static void main(String[] args) {
        fruit[0] = "grape";
        fruit[1] = "banana";
        fruit[2] = "apple";
        fruit[3] = "mango";
        fruit[4] = "watermelon";
        fruit[5] = "orange";

        Scanner sc = new Scanner(System.in);
        String input;
        input = sc.nextLine();

        if (isIn(input)) {
            //do something...
        } else {
            //do something else...
        }
    }

    public static boolean isIn(String input) {
        for(int i = 0; i < fruit.length; i++) {
            if (input.equals(fruit[i])) {
                return true;
            }
        }
        return false;
    }
}

Summarizing the suggestions given by others.

import java.util.Arrays;
import java.util.Scanner;

public class StringArrayTest {

   public static void main(String[] args) {

   String[] fruit = new String [] {"grape", "banana", "apple", "mango", "watermelon", "orange"};

   Scanner sc = new Scanner(System.in);
   String input = sc.nextLine();

   System.out.println(Arrays.asList(fruit).contains(input));
 }
}