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## Java Cheatsheet

Java is a general-purpose programming language that is widely used for developing desktop, web, and mobile applications. Here's a quick overview of its unique features and some code blocks for common tasks.

### Variables

Declare variables using the data type followed by the variable name. Java is a statically typed language, so the data type of a variable cannot be changed after it is declared.

int x = 10;

char c = 'a';

double d = 3.14;

### Functions

Functions in Java are declared using the `public static` keywords. They can take parameters and return values.

public static int add(int a, int b) {

return a + b;

}

### Loops

Java supports `for`, `while`, and `do-while` loops for iterating over arrays or performing a task a certain number of times.

int[] numbers = {1, 2, 3, 4, 5};

for (int i = 0; i < 5; i++) {

System.out.println(numbers[i]);

}

int i = 0;

while (i < 5) {

System.out.println(numbers[i]);

i++;

}

i = 0;

do {

System.out.println(numbers[i]);

i++;

} while (i < 5);

### Conditionals

Use `if` statements to execute code based on a condition. `else if` and `else` statements can be used to handle multiple conditions.

int x = 10;

if (x > 0) {

System.out.println("x is positive");

} else if (x < 0) {

System.out.println("x is negative");

} else {

System.out.println("x is zero");

}

### File Manipulation

Java provides built-in support for file manipulation, including reading and writing files, and interacting with the file system.

import java.io.File;

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Paths;

public class Main {

public static void main(String[] args) {

File file = new File("/path/to/file.txt");

try {

String contents = new String(Files.readAllBytes(Paths.get(file.getAbsolutePath())));

System.out.println(contents);

Files.write(Paths.get(file.getAbsolutePath()), "New contents".getBytes());

if (file.delete()) {

System.out.println("File deleted successfully");

} else {

System.out.println("Error deleting file");

}

} catch (IOException e) {

System.out.println("An error occurred");

e.printStackTrace();

}

}

}

### Resources

Here are some resources to help you learn more about Java:

- [Java Tutorials](https://docs.oracle.com/javase/tutorial/index.html)
- [Head First Java](https://www.amazon.com/Head-First-Java-Kathy-Sierra/dp/0596009208) (Book by Kathy Sierra and Bert Bates)
- [Codecademy Java Course](https://www.codecademy.com/learn/learn-java) (Interactive Java tutorial)