Question

[Java] I'm not sure how to implement the code. Please check my code at the bottom.

In this problem you will write several static methods to work with arrays and ArrayLists. Remember that a static method does not work on the instance variables of the class. All the data needed is provided in the parameters. Call the class Util. Notice how the methods are invoked in UtilTester.

public static int min(int[] array) gets the minimum value in the array

public static boolean contains(String[] array, String letter)determines if the array contains a word that starts with the given letter. Returns true if it does, otherwise returns false. The comparison is case-insensitive. 'A' and 'a' are counted as the same letter

public static ArrayList<String> contains(ArrayList<String> list, char letter)gets an ArrayList of all the strings in the given ArrayList that contain with the given letter. The comparison is case-insensitive. 'A' and 'a' are counted as the same letter

Use the following file:

UtilTester.java

import java.util.ArrayList;

public class UtilTester
{

   public static void main(String[] args)
   {
      //testing min method
      int[] numbers = {5, 8, 4, 6, 2, 1, 7, 3};
      System.out.println(Util.min(numbers));
      System.out.println("Expected: 1");

      int[] numbers2 = {2, 9, 4, 6, 5, 8, 7, 3};
      System.out.println(Util.min(numbers2));
      System.out.println("Expected: 2");

      int[] numbers3 = {10, 9, 4, 6, 5, 8, 7, 3};
      System.out.println(Util.min(numbers3));
      System.out.println("Expected: 3");

      //testing first contains
      String[] javaIdentifiers = {"Integer", "Double", "Float", "Char",
            "boolean", "long", "short", "byte"};
      System.out.println(Util.contains(javaIdentifiers,"c"));
      System.out.println("Expected: true");
      System.out.println(Util.contains(javaIdentifiers, "x"));
      System.out.println("Expected: false");
      System.out.println(Util.contains(javaIdentifiers,"B"));
      System.out.println("Expected: true");
      
      //testing second contains
      ArrayList<String> words = new ArrayList<String>();
      System.out.println(Util.contains(words, 'b'));
      System.out.println("Expected: []");
      words.add("Big");
      words.add("Java");
      words.add("is");
      words.add("best");
      words.add("Be");
      words.add("the");
      words.add("computer");
      words.add("CS46A/B");
      System.out.println(Util.contains(words, 'e'));
      System.out.println("Expected: [best, Be, the, computer]");
      System.out.println(Util.contains(words, 'B'));
      System.out.println("Expected: [Big, best, Be, CS46A/B]");
      System.out.println(Util.contains(words, 'a'));
      System.out.println("Expected: [Java, CS46A/B]");
      System.out.println(Util.contains(words, 'k'));
      System.out.println("Expected: []");

   }

}

[Here's my code]

import java.lang.reflect.Array;
import java.util.ArrayList;

public class Util
{
   public static int min(int[] array)
   {
       int min = array[0];
       for(int i = 0; i < array.length; i++)
       {
           if(min > array[i])
           {
               min = array[i];
           }
       }
       return min;
   }
   public static boolean contains(String[] array, String letter)
   {
       boolean returnValue = false;
       for(int i = 0; i < array.length; i++)
       {
           if(array[i].contains(letter.toLowerCase()))
           {
               returnValue = true;
           }
           else
           {
               returnValue = false;
           }
       }
       return returnValue;
   }
   public static ArrayList<String> contains(ArrayList<String> list, char letter)
   {
       for(int i = 0; i < list.size(); i++)
       {
           if(list.get(i).toString().substring(i, i + 1).equals(letter))
           {
               return ;
           }
       }
   }
  
}

Answer 1

package as3;

import java.util.ArrayList;

public class UtilTester
{

public static void main(String[] args)
{
//testing min method
int[] numbers = {5, 8, 4, 6, 2, 1, 7, 3};
System.out.println(Util.min(numbers));
System.out.println("Expected: 1");

int[] numbers2 = {2, 9, 4, 6, 5, 8, 7, 3};
System.out.println(Util.min(numbers2));
System.out.println("Expected: 2");

int[] numbers3 = {10, 9, 4, 6, 5, 8, 7, 3};
System.out.println(Util.min(numbers3));
System.out.println("Expected: 3");

//testing first contains
String[] javaIdentifiers = {"Integer", "Double", "Float", "Char",
"boolean", "long", "short", "byte"};
System.out.println(Util.contains(javaIdentifiers,"c"));
System.out.println("Expected: true");
System.out.println(Util.contains(javaIdentifiers, "x"));
System.out.println("Expected: false");
System.out.println(Util.contains(javaIdentifiers,"B"));
System.out.println("Expected: true");
  
//testing second contains
ArrayList<String> words = new ArrayList<String>();
System.out.println(Util.contains(words, 'b'));
System.out.println("Expected: []");
words.add("Big");
words.add("Java");
words.add("is");
words.add("best");
words.add("Be");
words.add("the");
words.add("computer");
words.add("CS46A/B");
System.out.println(Util.contains(words, 'e'));
System.out.println("Expected: [best, Be, the, computer]");
System.out.println(Util.contains(words, 'B'));
System.out.println("Expected: [Big, best, Be, CS46A/B]");
System.out.println(Util.contains(words, 'a'));
System.out.println("Expected: [Java, CS46A/B]");
System.out.println(Util.contains(words, 'k'));
System.out.println("Expected: []");

}

}

class Util
{
public static int min(int[] array)
{
int min = array[0];
for(int i = 0; i < array.length; i++)
{
if(min > array[i])
{
min = array[i];
}
}
return min;
}
public static boolean contains(String[] array, String letter)
{
boolean returnValue = false;
for(int i = 0; i < array.length; i++)
{
if(array[i].contains(letter.toLowerCase()))
{
returnValue = true;
}
else
{
returnValue = false;
}
}
return returnValue;
}
public static ArrayList<String> contains(ArrayList<String> list, char letter)
{
   ArrayList<String> words = new ArrayList<String>();
for(int i = 0; i < list.size(); i++)
{
  
// this is where you have made mistake you just return but you need to return list so i have defined one arraylist when in the list match withh the letter i will put that word into the new list and just return list
   if(list.get(i).toString().contains(Character.toString(letter)))
      
   words.add(list.get(i));
  
}
return words;
}
  
}