StringTokenizer Random Scanner Properties UUID in Java

StringTokenizer Random Scanner Properties UUID in Java

1. StringTokenizer

Used to split strings into tokens based on delimiters.
(Note: It’s a legacy class; String.split() or Scanner is usually preferred.)

import java.util.StringTokenizer;

public class Example {
    public static void main(String[] args) {
        String text = "Java,Python,C++";
        StringTokenizer st = new StringTokenizer(text, ",");
        
        while (st.hasMoreTokens()) {
            System.out.println(st.nextToken());
        }
    }
}

2. Random

Used to generate random numbers.

import java.util.Random;

public class Example {
    public static void main(String[] args) {
        Random rand = new Random();
        
        int randomInt = rand.nextInt(100); // random number between 0–99
        double randomDouble = rand.nextDouble(); // 0.0 – 1.0
        boolean randomBool = rand.nextBoolean();
        
        System.out.println(randomInt);
        System.out.println(randomDouble);
        System.out.println(randomBool);
    }
}

3. Scanner

Used for input (keyboard, file, etc.).

import java.util.Scanner;

public class Example {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        System.out.print("Enter your name: ");
        String name = sc.nextLine();
        
        System.out.print("Enter your age: ");
        int age = sc.nextInt();
        
        System.out.println("Hello " + name + ", you are " + age + " years old.");
        
        sc.close();
    }
}

4. Properties

Used to store key-value pairs (often for configuration files).

import java.util.Properties;

public class Example {
    public static void main(String[] args) {
        Properties props = new Properties();
        
        props.setProperty("username", "admin");
        props.setProperty("password", "12345");
        
        System.out.println("Username: " + props.getProperty("username"));
        System.out.println("Password: " + props.getProperty("password"));
    }
}

5. UUID

Generates unique identifiers.

import java.util.UUID;

public class Example {
    public static void main(String[] args) {
        UUID id1 = UUID.randomUUID(); // random UUID
        UUID id2 = UUID.randomUUID();
        
        System.out.println(id1.toString());
        System.out.println(id2.toString());
    }
}

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