
Basic difference between List and ArrayList is that List is an Interface and ArrayList is a Collection class. ArrayList implements List Interface.
Declaration and Initialization of List and ArrayList
import java.util.ArrayList;
import java.util.List;
public class Sample3 {
/**
* @param args
*/
public static void main(String[] args)
{
List<String> tempList=new ArrayList<String>();
tempList.add("Automation");
tempList.add("Manaual Testing");
tempList.add("Performance Testing");
}
}
Traversing values in the List
import java.util.ArrayList;
import java.util.List;
public class Sample3
{
public static void main(String[] args)
{
List<String> tempList=new ArrayList<String>();
tempList.add("Automation");
tempList.add("Manaual Testing");
tempList.add("Performance Testing");
// Access specific value from the List using get(index) method
// where index starts from 0
// Below statement will return third value (Performance Testing) from the list
System.out.println(tempList.get(2));
// Using foreach loop to traverse all the values in a List
for (String string : tempList) {
System.out.println(string);
}
}
}
Using List with Integer values
We can use all the methods as it is for integer values as well.
import java.util.ArrayList;
import java.util.List;
public class Sample3
{
public static void main(String[] args)
{
// Declare and Initialize for Integer values.
List<Integer> intList = new ArrayList<Integer>();
intList.add(50);
intList.add(80);
intList.add(100);
// Traversing all the integer values using foreach loop
for (Integer integer : intList) {
System.out.println(integer.intValue());
}
}
}
Other Useful methods in the ArrayList
Methods | Description | Example |
List<DataType> var=new ArrayList<DataType>(); | Declaration of List having String and Integer datatypes. | List<String> tempList = new ArrayList<String>(); List<Integer> intList = new ArrayList<Integer>(); |
add(String) add(Integer) | To add values in the list. | tempList.add("Data1"); |
add(index,value) | To add values at a specific position in the list. | tempList.add(3, "Data"); |
isEmpty() | Return True if the list is empty. Else return False. | tempList.isEmpty(); |
size() | Returns the total number of values present in the list | tempList.size(); |
get(index) | Returns the value present at the given index. | tempList.get(2); |
foreach loop | To traverse all the values in the list. | for (Integer value : intList) { System.out.println(value.intValue());} |
clear() | Used to remove all values from the list. | intList.clear(); |
remove(index) | Used to remove a value at the specified index. | intList.remove(2); |
set(index, newValue) | It replaces existing value with newValue at given index. | intList.set(1, 110); |
subList(fromIndex, toIndex) | Returns a sublist from the existing big list. It contains values fromIndex (including this index) till toIndex (excluding this index). | List<Integer> subList= intList.subList(0, 2); sublist will contain only 2 elements. |
indexOf(value) | Searches the given value in a list and returns its index values. | tempList.indexOf("Data")); intList.indexOf(80); |
lastIndexOf(value) | Searches the given value in a list and returns its last index values. | tempList.lastIndexOf("Data")); intList.lastIndexOf(80); |
Java Programs:
- Different ways to Reverse a String in Java.
- Copy formatting & style of cells from one sheet to another.
- Getting IP address and Hostname using InetAddress Class.
- User inputs via Command Prompt using arguments of main() method of a class.
- Program for List and ArrayList in Java.
- Useful methods and implementation under Scanner Class.
- Swapping two variable values without using any third variable.
- Difference between int x= 10 and y=010 in Java.
- Parameterized Constructors v/s Setter and Getter function in JAVA.
- Override a Static Method.
- TestNG – 1 || Introduction and benefits of TestNG Framework.
- TestNG – 2 || Installation process and a sample program of TestNG.
- TestNG – 3 || Create and execute multiple Test Cases.
- TestNG – 4 || Let’s understand @Test Annotation and attributes.
- TestNG – 5 || Understand Assertion in TestNG.
- TestNG – 6 || Use of @BeforeMethod and @AfterMethod.
- TestNG – 7 || Use of @BeforeClass and @AfterClass.
- TestNG – 8 || Creation and execution of Test Suites.
- TestNG – 9 || Let’s move deep into the Test Suites.
- TestNG – 10 || Use @BeforeTest and @AfterTest Annotations.
- TestNG – 11 || Groups attribute with @Test Annotation.
- TestNG – 12 || Use of @BeforeGroups & @AfterGroups.
- TestNG – 13 || Use of @BeforeSuite & @AfterSuite.
- TestNG – 14 || DataProvider annotation & attribute.
- TestNG – 15 || DataProvider with parameters.
- TestNG – 16 || Access data from Excel sheet using DataProvider.
- TestNG – 17 || Passing multiple Parameters in testng xml.
- TestNG – 18 || Multiple Browser and Parallel Execution in TestNG.
- TestNG -19 || Concept of Parallel Execution.
- TestNG – 20 || Run TestNG Program using main() method.
- Computer Basics -1 || Introduction and Structure of Computer.
- Computer Basics -2 || Types of Computers and Usage.
- Computer Basics -3 || What are the different types of Software?
- Computer Basics -4 || Importance of Operating System(OS).
- Computer Basics -5 || Understanding of Number System.
- Computer Basics -6 || Understanding MS-DOS Commands.
- Computer Basics -7 || Important Features of MS-Word.
- Computer Basics -8 || Let’s learn the usage of MS-Excel.
- Computer Basics -9 || Understand and Implement Data Validation in Excel.
- Computer Basics -10 || How to apply Filter in a data set in Excel?
- Computer Basics -11 || Using Charts in place of Data Tables in Excel.
- Computer Basics -12 || Advantages of PivotCharts over Simple Charts in Excel.
- Computer Basics -13 || Creating pivot charts/tables in Excel.
- Abbreviations to Full-Forms in Computer Basics.
- Basic Java – 1 || Understand Java before start learning JAVA.
- Basic Java – 2 || Variables and Data Types used in JAVA.
- Basic Java – 3 || Understanding Class, Objects, Methods in Java.
- Basic Java – 4 || More on methods(Return Type and Parameters)
- Basic Java – 5 || Methods- Call by Value and Call by Reference in Java.
- Basic Java – 6 || Understanding of Constructor and Destructor in JAVA.
- Basic Java – 7 || Static Variables and Methods.
- Basic Java – 8 || Lets learn about Arrays in Java.
- Basic Java – 9 || Performing multiple operations using Java Operators.
- Basic Java – 10 || Conditions (If and Switch) in JAVA.
- Basic Java – 11 || for and for-each in Java. (Loops Part-1)
- Basic Java – 12 || Alternate looping concepts while and do-while. (Loops Part-2)
- Basic Java – 13 || Decimal values v/s Octal base(8) values in JAVA.
- Basic Java – 14 || Learn about String literals in Java.
- Basic Java – 15 || Runtime User Input using Scanner Class (Part-1).
- Basic Java – 16 || Runtime User Input using BufferedReader Class (Part-2).
- Basic Java – 17 || Runtime User Input using Console Class (Part-3).
- Basic Java – 18 || Difference between break and continue keywords.
- Basic Java – 19 || Sending Email using Java (Part-1).
- Basic Java – 20 || Sending Email with attachment using Java (Part-2).
- Basic Java – 21 || Stack memory and Heap memory in Java.
- Basic Java – 22 || Let’s learn more about String.
- Basic Java – 23 || String, StringBuffer & StringBuilder in Java.
- Basic Java – 24 || Exception Handling using Try Catch.
- File Handling | Reading data from word document(.doc or .docx) in JAVA.
- File Handling | Reading data from Excel files (.xls or .xlsx) using JAVA.
- File Handling | Writing data into an Excel(.XLSX or .XLS) File.
- File Handling | Implement formatting in Excel using Java.
- File Handling | Copy existing data from one workbook to another workbook in Java.
- File Handling | Reading data from PDF file using JAVA.
- File Handling || Traverse folders and subfolders in Java.
- File Handling || Reading and Writing data from a text file.
- File Handling || Multiple file creation using template based input data.
- Framework || Simple example of Key Driven Framework using excel sheet in Selenium(JAVA).
- QnA || How to use Constructors in Abstract class?
- QnA | Difference between Integer and int keywords.
- QnA | Can main method be overloaded?
- QnA | How do I reverse a String/Sentence in Java?
- QnA | Perform Multiplication and Division without * or / or % operators.
- QnA | How do I get the default value of data type?
- QnA | How to split String if it contains period symbol (.) in between?
- Different ways to Reverse a String in Java.
- Copy formatting & style of cells from one sheet to another.
- Getting IP address and Hostname using InetAddress Class.
- User inputs via Command Prompt using arguments of main() method of a class.
- Program for List and ArrayList in Java.
- Useful methods and implementation under Scanner Class.
- Swapping two variable values without using any third variable.
- Difference between int x= 10 and y=010 in Java.
- Parameterized Constructors v/s Setter and Getter function in JAVA.
- Override a Static Method.
- Selenium-10 || Taking Screenshots using Selenium
- Selenium-9 || Understanding WebDriver API.
- Selenium-8 || Implementing Wait(s) in Selenium.
- Selenium-7 || Let’s learn to create complex XPath.
- Selenium-6 || XPath is the best way to locate web elements.
- Selenium-5 || Locating web elements using various type of Locators.
- Selenium-4 || Handling multiple web browsers.
- Selenium-3 || First program using Selenium Web Driver.
- Selenium-2 || Let’s learn Selenium IDE.
- Selenium-1 || Understanding Selenium and Selenium WebDriver.
- JIRA Tutorials-2 || Implement Search and Filter on JIRA Issues.
- JIRA Tutorials-1 || Basic understanding of JIRA.