Write a program that reads a 4-bit binary number from the keyboard as a string and then converts it into decimal. For example, if the input is 1100, the output should be 12. (Hint: Break the string into substrings and then convert each substring to a value for a single bit. If the bits are b0, b1, b2, and b3, the decimal equivalent is 8b0 + 4b1 + 2b2 + b3.)

import java. util. Scanner;

public class ss11{

public static void main (String[]args) {

Scanner keyboard = new Scanner (System. in)

String a1, a2, a3, a4, a5;

int i1, i2, i3, i4, i5;

System. out. println ("Enter a four bit binary number:");

a1 = keyboard. next ();

a2 = a1. substring (0,1);

a3 = a1. substring (1,2);

a4 = a1. substring (2,3);

a5 = a1. substring (3,4);

i1 = Integer. parseInt (a2);

i2 = Integer. parseInt (a3);

i3 = Integer. parseInt (a4);

i4 = Integer. parseInt (a5);

i1 = i1 * 8;

i2 = i1 * 4;

i3 = i1 * 2;

i4 = i1 * 1;

i5 = i1+i2+i3+i4;

System. out. println ("The converted decimal number is: + i5);

}

}