Java for Testing
Java for test automation: basics, OOP, keywords, strings, collections, exceptions and programs.
How to Install Java JDK on Windows, Mac and Linux (2026 Guide for Testers)
Install Java JDK 21 on Windows, macOS or Linux, set JAVA_HOME and PATH correctly, verify with java and javac, and fix the errors testers hit most often.
static and final Keywords in Java: Variables, Methods, Blocks and Classes
The static and final keywords in Java: static variables, methods, blocks and nested classes; final variables, references, methods and classes, with examples.
Strings in Java: String Pool, Immutability, StringBuilder and All String Methods
How Java strings work: the string pool, why String is immutable, == vs equals, String vs StringBuilder vs StringBuffer, and every common String method.
Java Enums and Inner Classes: Types, Examples and When to Use Them
Java enums with fields, methods and switch, plus the four kinds of nested classes: inner, static nested, local and anonymous, with practical examples.
Java Date and Time API (java.time): LocalDate, LocalDateTime, ZonedDateTime, Duration and Formatting
The java.time API with examples: LocalDate, LocalDateTime, ZonedDateTime, Instant, Duration and Period, formatting and parsing, and time zones in tests.
Java Certifications Guide (2026): Oracle Java SE 17 and 21, Plus Certifications for SDETs
Which Java certification to take: Oracle Java SE 21 and 17 Developer (OCP), Java Foundations, and certifications useful for SDETs.
OOPs Concepts in Java: Encapsulation, Inheritance, Polymorphism and Abstraction
The four OOPs concepts in Java explained with code: encapsulation, inheritance, polymorphism (overloading vs overriding) and abstraction.
What Is Java? History, Key Features and Why Testers Use It
What Java is and how it works: history from Sun to Oracle, bytecode and the JVM, the key features of Java explained, where it is used, and why testers learn it.
Java Operators and Expressions: Types, Precedence and Common Traps
Java operators with examples: arithmetic, relational, logical, assignment, ternary and instanceof, the precedence table, and traps like == and integer division.
Control Flow Statements in Java: if, switch, Loops, break and continue
Java control flow statements with examples: if-else, switch and switch expressions, for, for-each, while, do-while, break, continue and labeled loops.
Classes and Objects in Java: Fields, Constructors, Methods and Records
Classes and objects in Java explained: fields, methods, constructors, references, static vs instance, this, a page object example, and records for test data.
How to Read a File in Java: Scanner, Files and BufferedReader
Read files in Java with Scanner, Files.readString, readAllLines, Files.lines and BufferedReader, load CSV test data for TestNG, and fix path and encoding bugs.
Java SE vs Java EE (Jakarta EE) vs Java ME: Differences Explained
Java SE vs Java EE (now Jakarta EE) vs Java ME: what each edition contains, the javax to jakarta change, which one testers need, and a quick comparison table.
Java Keywords: Complete List of All 51 Reserved Keywords (with Examples)
Complete list of Java keywords: all 51 reserved keywords with meanings, contextual keywords like var and record, examples, common mistakes and FAQs.
Hello World in Java: Your First Program and the Structure of a Java Program
Write and run your first Java Hello World program, understand every part of a Java program's structure, and fix the 4 errors beginners hit most.
Primitive Data Types in Java: Sizes, Ranges, Defaults and Common Traps
All 8 primitive data types in Java with size, range and default value, verified with real Java output, plus overflow, integer division and float traps.
Count Vowels and Consonants in Java | Step-by-Step Guide with Code Examples
Learn how to count vowels and consonants in Java strings. Includes multiple methods, code examples, and handles uppercase, lowercase, and special characters.
Java Strings, Encoding (UTF-8), Wrapper Classes and Exception Handling
Java strings and immutability, string encoding and charsets (UTF-8 vs ISO-8859-1), StringBuilder, wrapper classes and exception handling — with examples.
Interfaces in Java: Comparable, Default Methods, Nested & Final
Interfaces in Java: Comparable and Comparator (and the compareTo overflow bug), Java 8 default methods, why interfaces can't be instantiated or final.
Java Access Modifiers and super Keyword: OOP Keywords Explained with Examples
Java access modifiers (private, default, protected, public) and the super keyword, with a comparison table, overriding rules and Selenium examples.
How Java Code Runs: Compilation Process, JVM and Platform Independence
The Java compilation process step by step: javac turns .java into bytecode, the class loader and JVM verify and run it, and the JIT compiler makes it fast.
Java Basics: Variables, Objects, Data Types and Loops (With Examples)
Java basics for testers: instance, static and local variables, creating objects, primitive vs non-primitive data types, and while vs do-while loops.