feat: Add Comparable Example

JavaDsaWithTest/src/main/java/org/practice/dsa/collections/ComparableDemo.java

@@ -0,0 +1,45 @@
+package org.practice.dsa.collections;
+
+public class ComparableDemo implements Comparable<ComparableDemo> {
+    private int id;
+    private String name;
+
+    public ComparableDemo(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int compareTo(ComparableDemo o) {
+//        if (this.id > o.id) {
+//            return 1;
+//        }
+//        if (this.id < o.id) {
+//            return -1;
+//        }
+//        return 0;
+
+        return Integer.compare(this.id, o.id);
+    }
+
+    @Override
+    public String toString() {
+        return "Student{id=" + id + ", name='" + name + "'}";
+    }
+}

JavaDsaWithTest/src/main/java/org/practice/dsa/collections/ComparableExample.java

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+package org.practice.dsa.collections;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+public class ComparableExample {
+    public static void main(String[] args) {
+        List<ComparableDemo> demo = new ArrayList<>();
+        demo.add(new ComparableDemo(3, "V"));
+        demo.add(new ComparableDemo(1, "B"));
+        demo.add(new ComparableDemo(2, "X"));
+
+        Collections.sort(demo);
+        demo.forEach(System.out::println);
+    }
+}

JavaDsaWithTest/src/main/java/org/practice/dsa/collections/ComparatorAndComparable.md

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+Both Comparator and Comparable are used to save the custom sorting logic in Java.
+
+## Comparable:
+- Purpose: To define the natural ordering of objects of a class. 
+- Interface: Found in `java.lang`.
+- Method: `int compareTo(T o);`
+- Modifies Class: The class itself implement `Comparable` interface.