ArrayList Methods

1.Adding Elements

ArrayList<String> list = new ArrayList<>();
list.add("Apple");
System.out.println(list); --> output:[Apple]

2.Accessing Elements

ArrayList<String> list = new ArrayList<>();
list.add("Apple");

String item = list.get(0);
System.out.println(item); -->output:Apple

3. Updating Elements

import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {

        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");

        list.set(0, "Mango");   // replace element

        System.out.println(list);
    }
}  

output:[Mango, Banana]

4. Removing Elements

import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {

        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");
        list.add("Mango");

        list.remove(0);          // remove by index
        System.out.println(list);

        list.remove("Banana");   // remove by value
        System.out.println(list);

        list.clear();            // remove all
        System.out.println(list);
    }
}

  output:[Banana, Mango]
         [Mango]
         []

5. Size & Check

import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {

        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");

        System.out.println(list.size());           // number of elements
        System.out.println(list.isEmpty());        // check empty
        System.out.println(list.contains("Apple"));// check element
    }
}

output:2
       false
       true

6. Searching

 import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {

        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");
        list.add("Apple");

        System.out.println(list.indexOf("Apple"));      // first index
        System.out.println(list.lastIndexOf("Apple"));  // last index
    }
}

output:0
       2

7. Bulk Operations

import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {

        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");
        list.add("Apple");

        System.out.println(list.indexOf("Apple"));      // first index
        System.out.println(list.lastIndexOf("Apple"));  // last index
    }
}

output:[Apple, Banana, Grapes]
       [Apple, Banana]
       [Grapes]