String reversed = new StringBuilder(str).reverse().toString();

boolean isPalindrome = str.equalsIgnoreCase(new StringBuilder(str).reverse().toString());

int max = list.stream().max(Integer::compareTo).orElseThrow();

String result = Stream.of(opt1, opt2, opt3)
        .filter(Optional::isPresent)
        .map(Optional::get)
        .findFirst()
        .orElse("default");

List<String> upper = list.stream()
        .map(String::toUpperCase)
        .toList();

long count = Arrays.stream(sentence.split("\\s+"))
        .filter(w -> w.equalsIgnoreCase("java"))
        .count();

int otp = 100000 + new Random().nextInt(900000);

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🆔 @javapro_ir
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🆔 @javapro_ir
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🆔 @javapro_ir
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🆔 @javapro_ir
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public class Car {
    public static int totalCars = 0;  // Static
    private String model;             // Instance

    public Car(String model) {
        this.model = model;
        totalCars++;
    }

    public String getModel() {
        return model;
    }
}

Car c1 = new Car("BMW");
Car c2 = new Car("Audi");

System.out.println(Car.totalCars);  // 2
System.out.println(c1.getModel());  // BMW
System.out.println(c2.getModel());  // Audi

double result = Math.sqrt(25);  // بدون ایجاد شیء

#کاربر_مبتدی

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🆔 @javapro_ir
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هیچ‌وقت برای هزینه‌ای که صرف رشد و پیشرفت خودت می‌کنی تردید و دودوتاچهارتا نکن.

🆔 @javapro_ir
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@Service
public class MessageService {

    private final Messenger messenger;

    public MessageService(Messenger messenger) {
        this.messenger = messenger;
    }

    public void send() {
        messenger.sendMessage("Hello Spring");
    }
}

mvn spring-boot:run

#Spring

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src
 └── main
      ├── java
      │    └── com.example.demo
      │           ├── DemoApplication.java
      │           ├── controller
      │           ├── service
      │           └── repository
      └── resources
           ├── application.properties
           └── static / templates

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

mvn spring-boot:run

https://localhost:8080

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello Spring Boot!";
    }
}

#Spring

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