stringBuilder.java

//Question: ALL ABOUT STRING BUILDER
package stringBuilder;

import java.util.Scanner;

public class stringBuilder {
    public static void main(String[] args) {
        //Initialisation
        String s = "Raj Sarkar";  // (String)
        StringBuilder sb = new StringBuilder("abc");  // (String builder)
        System.out.println(sb);

        //Built in functions
        System.out.println(sb.length());  // prints length
        StringBuilder xy = new StringBuilder("");  // creating an empty string builder
        System.out.println(xy.length());    // Output: 0
        System.out.println(xy.capacity());  // prints capacity. initially, the capacity of an empty string builder is 16
        System.out.println(sb.capacity());  // Output: initial capacity + number of character = 19
        StringBuilder ab = new StringBuilder(10);  // we can also initialise a string builder with a given capacity
        System.out.println(ab.capacity());  // Output: 10
        System.out.println(sb.compareTo(xy));  // Output: 3 (Because xy is an empty String Builder)
        System.out.println(sb.reverse());  // Output: cba
         System.out.println();
         // baki jo jo string main tha wo sab yaha bhi hai 

        //Taking input
        Scanner sc = new Scanner(System.in);
        StringBuilder rs = new StringBuilder(sc.nextLine());  // Method 1
        System.out.println(rs);
        System.out.println();

        String t ;
        t = sc.nextLine();
        StringBuilder tb = new StringBuilder(t);  // Method 2
        System.out.println(tb);
        System.out.println();
        
        //setCharAt()
        sb.setCharAt(2, 'd');  // Here we can change individual index without creating anything new
        System.out.println(sb);  // Output: "cbd"
    }
    
}