Bilkul bhai, StringBuffer ko bhi simple example aur clear explanation ke saath samjhata hoon. Agar tu StringBuilder samajh gaya hai, to StringBuffer samajhna aur bhi easy ho jayega, kyunki dono kaafi similar hain.

StringBuffer Kya Hai?

• StringBuffer bhi ek mutable string class hai, jaise StringBuilder.
• Iska kaam bhi wahi hai: Strings ko modify karna bina naye objects create kare.
• Farak? StringBuffer thread-safe hota hai, matlab ye multi-threaded environments ke liye secure hai, lekin ye StringBuilder se thoda slow hota hai.

StringBuffer vs StringBuilder

StringBuffer Example

Without StringBuffer (Using String)

Baar-baar string modify karne pe naye objects bante hain, jo memory aur time waste karta hai.

public class WithoutStringBuffer {
    public static void main(String[] args) {
        String s = "Hello";
        s = s + " World";  // Naya object ban raha hai
        s = s + "!";
        System.out.println(s);  // Output: Hello World!
    }
}

With StringBuffer

StringBuffer ek hi object ko baar-baar modify karta hai.

public class WithStringBuffer {
    public static void main(String[] args) {
        StringBuffer sb = new StringBuffer("Hello");
        sb.append(" World");  // "World" add karega existing object mein
        sb.append("!");
        System.out.println(sb);  // Output: Hello World!
    }
}

Yahan koi naya object nahi bana, performance better hai.

Important Methods of StringBuffer

1. append()

String ke end mein kuch add karne ke liye.

StringBuffer sb = new StringBuffer("Hello");
sb.append(" World");
System.out.println(sb);  // Output: Hello World

2. insert()

String ke specific index par kuch insert karne ke liye.

StringBuffer sb = new StringBuffer("Hello World");
sb.insert(6, "Beautiful ");  // Index 6 par "Beautiful " insert karega
System.out.println(sb);  // Output: Hello Beautiful World

3. replace()

String ke ek portion ko replace karne ke liye.

StringBuffer sb = new StringBuffer("I love Java");
sb.replace(7, 11, "Python");  // "Java" ko "Python" se replace karega
System.out.println(sb);  // Output: I love Python

4. delete()

String ke specific portion ko delete karne ke liye.

StringBuffer sb = new StringBuffer("Hello Beautiful World");
sb.delete(6, 16);  // Index 6 se 15 tak delete karega
System.out.println(sb);  // Output: Hello World

5. reverse()

String ko reverse karne ke liye.

StringBuffer sb = new StringBuffer("Java");
sb.reverse();
System.out.println(sb);  // Output: avaJ

6. capacity()

StringBuffer ki capacity check karne ke liye.

StringBuffer sb = new StringBuffer();
System.out.println(sb.capacity());  // Default capacity: 16

sb.append("Java Programming");
System.out.println(sb.capacity());  // Capacity dynamically grow karegi

Thread-Safety of StringBuffer

Thread-safety ka matlab hai ki agar ek StringBuffer object ko multiple threads access karte hain, to usme koi data corruption nahi hoga. Java internally synchronized blocks use karta hai, jo ensure karta hai ki ek time pe ek hi thread object ko modify kare.

StringBuffer vs StringBuilder: Example

Agar tumhare program mein multi-threading use ho raha hai, to StringBuffer use karo.

public class ThreadSafeExample {
    public static void main(String[] args) {
        StringBuffer sb = new StringBuffer("Hello");
        
        // Thread 1
        new Thread(() -> {
            sb.append(" World");
            System.out.println(sb);
        }).start();
        
        // Thread 2
        new Thread(() -> {
            sb.append("!");
            System.out.println(sb);
        }).start();
    }
}

Yahan pe StringBuffer thread-safe hai, isliye threads ke beech koi issue nahi hoga. Agar yahi StringBuilder hota, to data corruption ho sakti thi.

When to Use StringBuffer?

1. Multi-threaded Applications: Agar tumhare program mein multiple threads ek hi string object ke saath kaam karte hain, to StringBuffer use karo.
2. Repeated String Modifications: Agar string baar-baar modify karni hai aur thread-safety chahiye.

Summary

• StringBuffer mutable hai, aur multi-threading ke liye safe hai.
• Agar tum single-threaded program likh rahe ho, to StringBuilder faster hoga.
• Agar tum immutable strings chahiye (jise modify nahi karna), to String use karo.

Agar koi specific doubt ho ya code chahiye, to bata!