Rico derusting pull

src/ArrayPractice.java

@@ -1,22 +1,13 @@
 public class ArrayPractice {
   public static void main(String[] args) {
-    // Create an array of Strings of size 4
-
-    // Set the value of the array at each index to be a different String
-    // It's OK to do this one-by-one
-
-    // Get the value of the array at index 2
-
-    // Get the length of the array
-
-    // Iterate over the array using a traditional for loop and print out each item
-
-    // Iterate over the array using a for-each loop and print out each item
-
-    /*
-     * Reminder!
-     * 
-     * Arrays start at index 0
-     */
+    String[] cueists = {"Efren","Francisco","Johann","AJ"};
+    System.out.println(cueists[2]);
+    System.out.println(cueists.length);
+    for (int i=0; i < cueists.length; i++) {
+      System.out.println(cueists[i]);
+    }
+    for (String cueist : cueists) {
+      System.out.println(cueist);
+    }
   }
 }

src/ListPractice.java

@@ -1,36 +1,31 @@
+import java.util.*;
+
 public class ListPractice {
 
 
   public static void main(String[] args) {
-    // Create an empty ArrayList of Strings and assign it to a variable of type List
-
-    // Add 3 elements to the list (OK to do one-by-one)
-
-    // Print the element at index 1
-
-    // Replace the element at index 1 with a new value
-    // (Do not insert a new value. The length of the list should not change)
-
-    // Insert a new element at index 0 (the length of the list will change)
-
-    // Check whether the list contains a certain string
-
-    // Iterate over the list using a traditional for-loop.
-    // Print each index and value on a separate line
-
-    // Sort the list using the Collections library
-
-    // Iterate over the list using a for-each loop
-    // Print each value on a second line
-
-    /*
-     * Usage tip!
-     * 
-     * Use a traditional for-loop when you need to use the index or you need to iterate in an
-     * unconventional order (e.g. backwards)
-     * 
-     * Otherwise, if you're iterating the in the conventional order and don't need the
-     * index values a for-each loop is cleaner.
-     */
+
+    ArrayList<String> poolEquipment = new ArrayList<>();
+    poolEquipment.add("Cue");
+    poolEquipment.add("Pool Balls");
+    poolEquipment.add("Chalk");
+    System.err.println(poolEquipment);
+
+    System.out.println(poolEquipment.get(1));
+    poolEquipment.set(1,"Pool Table");
+    System.err.println(poolEquipment);
+    poolEquipment.add(0, "Glove");
+    System.err.println(poolEquipment);
+
+    for (int i=0;i<poolEquipment.size();i++) {
+      System.out.println(poolEquipment.get(i));
+    }
+
+    poolEquipment.sort(null);
+    System.out.println(poolEquipment);
+
+    for (String equipment : poolEquipment) {
+        System.out.println(equipment);
+    }
   }
 }

src/MapPractice.java

@@ -1,43 +1,31 @@
-
+import java.util.*;
 
 public class MapPractice {
   public static void main(String[] args) {
-    // Create a HashMap with String keys and Integer values and
-    // assign it to a variable of type Map
-
-    // Put 3 different key/value pairs in the Map
-    // (it's OK to do this one-by-one)
-
-    // Get the value associated with a given key in the Map
-
-    // Find the size (number of key/value pairs) of the Map
-
-    // Replace the value associated with a given key (the size of the Map shoukld not change)
-
-    // Check whether the Map contains a given key
-
-    // Check whether the Map contains a given value
-
-    // Iterate over the keys of the Map, printing each key
-
-    // Iterate over the values of the map, printing each value
-
-    // Iterate over the entries in the map, printing each key and value
-
-    /*
-     * Usage tip!
-     * 
-     * Maps are great when you want a specific key to value mapping.
-     * Example: The key could be a person's name, and the value could be their phone number
-     * 
-     * However if your keys are simple ascending 0-indexed integers with no gaps
-     * (0, 1, 2, 3, 4...) then an array or List is likely a better choice.
-     * Example: If you want to store the order of songs in a playlist.
-     * 
-     * If you're finding that you're just wanting to store unordered values and the keys
-     * are unimportant, a Set may be a better choice.
-     * Example: If you want to hold the student ID numbers of everyone in a course,
-     * and you don't care about any ordering.
-     */
+    HashMap<String,Integer> contactID = new HashMap<>();
+
+    contactID.put("Johann",00);
+    contactID.put("Efren",01);
+    contactID.put("Francisco",02);
+
+    System.out.println(contactID.get("Efren"));
+
+    System.out.println(contactID.size());
+
+    contactID.put("Francisco",04);
+    System.out.println(contactID.get("Francisco"));
+
+    System.out.println("Does the HashMap Contain Efren? " + contactID.containsKey("Efren"));
+    System.out.println("Does the HashMap Contain 05? " + contactID.containsValue(05));
+
+    for (String i : contactID.keySet()) {
+      System.out.println(i);
+    }
+    for (Integer k : contactID.values()) {
+      System.out.println(k);
+    }
+    for (String j : contactID.keySet()) {
+      System.out.println("Keys: " + j + " Values: " + contactID.get(j));
+    }
   }
 }

src/NumberPractice.java

@@ -1,25 +1,21 @@
+
 public class NumberPractice {
   public static void main(String args[]) {
-    // Create a float with a negative value and assign it to a variable
-
-    // Create an int with a positive value and assign it to a variable
-
-    // Use the modulo % operator to find the remainder when the int is divided by 3
-
-    // Use the modulo % operator to determine whether the number is even
-    // (A number is even if it has a remainder of zero when divided by 2)
-    // Use an if-else to print "Even" if the number is even and "Odd"
-    // if the number is odd.
+    double numFloat = -1.2;
+    int numInt = 4;
 
-    // Divide the number by another number using integer division
+    System.out.println(numFloat);
+    System.out.println(numInt);
 
-    /*
-     * Reminder!
-     * 
-     * When dividing ints, the result is rounded down.
-     * Example: 
-     * 7 / 3 = 2 when performing int division
-     */
+    System.out.println(numInt%2);
+
+    if (numInt%2==0) {
+      System.out.println(numInt + " is even!");
+    }
+    else {
+      System.out.println(numInt + " is negative!");
+    }
 
+    System.out.println(numFloat/4);
   }
 }

src/Person.java

@@ -1,20 +1,28 @@
-/*
- * In this file you will follow the comments' instructions to complete
- * the Person class.
- */
 
 public class Person {
-  // Declare a public String instance variable for the name of the person
-  // Declare a private int instance variable for the age of the person
-
-
-  // Create a constructor that takes the name and age of the person
-  // and assigns it to the instance variables
+  public String name;
+  private final int age;
+
+  public Person(String name, int age) {
+    this.name = name;
+    this.age = age;
+  }
 
+  public String getName() {
+    return name;
+  }
 
-  // Create a toString method that gives the name and age of the person
+  public int getAge() {
+    return age;
+  }
 
+  public String string() {
+    return name + age;
+  }
 
+  public int birthyear(int currentyear) {
+    return currentyear - age;
+  }
   // Implement the below public instance method "birthYear"
   // There should NOT be any print statement in this method.
   /**
@@ -31,22 +39,17 @@ public class Person {
 
 
   public static void main(String[] args) {
-    // Create an instance of Person
-
-    // Create another instance of Person with a different name and age and
-    // assign it to a different variable
-
-    // Print the first person
-
-    // Print the second person
-
-    // Get the name of the first person and store it in a local variable
-
-    // Using the birthYear method, get the birth year of the first person
-    // and store it in a local variable. Input the actual current year (e.g. 2025)
-    // as the argument.
-
-    // In a separate statement, print the local variable holding the birth year.
+    Person person1 = new Person("RJ",20);
+    Person person2 = new Person("Yao",19);
+
+    System.out.println(person1.string());
+    System.out.println(person2.string());
+
+    String person1name = person1.getName();
+    System.out.println(person1name);
+
+    int byear = person1.birthyear(2025);
+    System.out.println(byear);
 
     /**
      * Terminology!

src/SetPractice.java

@@ -1,13 +1,21 @@
+import java.util.*;
+
 public class SetPractice {
   public static void main(String[] args) {
-    // Create a HashSet of Strings and assign it to a variable of type Set
+    HashSet<String> set = new HashSet<>();
+    set.add("Philippines");
+    set.add("USA");
+    set.add("Canada");
 
-    // Add 3 elements to the set
-    // (It's OK to do it one-by-one)
+    System.out.println("Contains Philippines? " + set.contains("Philippines"));
+
+    set.remove("USA");
 
-    // Check whether the Set contains a given String
+    System.out.println("Size of the HashSet: " + set.size());
 
-    // Remove an element from the Set
+    for (String i : set) {
+      System.out.println(i);
+    }
 
     // Get the size of the Set
 

src/StringPractice.java

@@ -1,32 +1,29 @@
-public class StringPractice {
-  public static void main(String[] args) {
-    // Create a string with at least 5 characters and assign it to a variable
-
-    // Find the length of the string
 
-    // Concatenate (add) two strings together and reassign the result
+import java.util.Arrays;
 
-    // Find the value of the character at index 3
+public class StringPractice {
+  public static void main(String[] args) {
+    String word = "Billiards";
+    System.out.println("Length of word: " + word.length());
 
-    // Check whether the string contains a given substring (i.e. does the string have "abc" in it?)
+    String word2 = "Snooker";
 
-    // Iterate over the characters of the string, printing each one on a separate line
+    System.out.println(word.concat(word2));
 
-    // Create an ArrayList of Strings and assign it to a variable
+    System.out.println(word.charAt(3));
 
-    // Add multiple strings to the List (OK to do one-by-one)
+    String subString = "abc";
+    System.out.println("Does string contain: " + subString + "? " + word.contains(subString));
 
-    // Join all of the strings in the list together into a single string separated by commas
-    // Use a built-in method to achieve this instead of using a loop
+    char[] charArray = word.toCharArray();
+    for (int i = 0; i < charArray.length; i++) {
+      System.out.println(charArray[i]);
+    }
 
-    // Check whether two strings are equal
+    String[] wordList = {"Carom","Bank","Billiard","Kick","Masse"};
+    String arrStr = Arrays.toString(wordList);
+    System.out.println(arrStr);
 
-    /*
-     * Reminder!
-     * 
-     * When comparing objects in Java we typically want to use .equals, NOT ==.
-     * 
-     * We use == when comparing primitives (e.g. int or char).
-     */
+    System.out.println("Strings equal? " + word.equals(word2));
   }
 }