Java Tutorials

Java: Could Not Find Or Load Main Class

When working with Java, the final execution of code happens via pre-compiled classes. Once you write a class in Java, the compiler converts your high-level source code into…
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How to Solve java.lang.NullPointerException Error

You must have come across something called a NullPointerException if you have worked on Java-based applications. The Null Pointer Exception is one of the most common errors…
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Java indexOf(): A How-To Guide

The Java indexOf() method finds the index position at which a specified string begins. This method lets you find a string within another string. If the value you specify is…
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Java Selection Sort: A How-To Guide

The Java selection sort finds the smallest item in a list and moves that value to the start of the list. This happens repeatedly until every element in the first list has…
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Java break Statement: A How-To Guide

A Java break statement halts the execution of a loop. When a break statement is run, a program starts to run the code after a statement. If a break statement is used in a…
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Java Ternary Operator: A Step-By-Step Guide

The Java ternary operator lets you write an if statement on one line of code. A ternary operator can either evaluate to true or false. It returns a specified value depending…
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Learn to Sort ArrayList in Java

The Collections.sort() method sorts a Java ArrayList in ascending order. Collections.reverse() reverses the order of a Java ArrayList. You need to import the Java Collections…
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How to Use the Java continue Statement

The Java continue statement stops one iteration in a loop and continues to the next iteration. This statement lets you skip particular iterations without stopping a loop entirely….
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How to Convert a Java String to Char Array

The toCharArray() method converts a string to a char array in Java. This method lets you manipulate individual characters in a string as list items. Spaces, numbers, letters,…
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Java User Input and Scanner Class: A Step-By-Step Guide

The Scanner class is used to read Java user input. Java Scanner is built into the java.util package, so no external libraries are needed to use it. Scanner reads text from…
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A Step-By-Step Guide to charAt in Java

The Java charAt() method returns a character at a specific index position in a string. The first character in a string has the index position 0. charAt() returns a single…
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How to Use Java Math.random

The Math.random()Java method generates a pseudorandom number between 0.0 and 1.0. The resulting random number can be multiplied to get a range outside 0-1, and the result…
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Java Substring: A How-To Guide

The Java substring() method returns a portion of a particular string. This method accepts the start and end index values of the characters you would like to retrieve from…
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How to Use Enum in Java

A Java enum is a data type that stores a list of constants. You can create an enum object using the enum keyword. Enum constants appear as a comma-separated list within a…
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Java Stack Class

A Java stack is a last-in, first-out data structure. The first item removed from a stack is the item last added to the stack. A stack data structure adds new items to the…
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Java Hello World: A Guide for Beginners

Welcome to the Java programming language. The first task any beginner should take on is the “Hello, World!” script. In this task, you have to print a message to the console….
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Java Compilers: A Step-By-Step Guide

Five to ten years ago, learning Java wasn’t as accessible as it is now. Back then, you had to download a Java Development Kit (JDK) that contained the compiler and interpreter…
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Fibonacci Java: A Guide

A Guide to the Fibonacci Java Algorithm The Fibonacci Sequence is a sequence where the next number is calculated by calculating the sum of the previous two numbers. This sequence…
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Java String replace() Method: A Step-By-Step Guide

The Java string replace() method will replace a character or substring with another character or string. The syntax for the replace() method is string_name.replace(old_string,…
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How to Convert a Char to String in Java

To convert a char to a string in Java, the toString() and valueOf() methods are used. The toString() and valueOf() methods are both used to convert any data type to a string….
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