Here is a Java program to convert binary number to decimal number using Integer.parseInt method.
We have to convert a binary number( base 2) to decimal number (base 10). Binary number system is a base 2 number system using digits 0 and 1 whereas Decimal number system is base 10 and using digits from 0 to 9. Given a binary number as input from user convert it to decimal number.
Input Binary Number 0101 Decimal Number 5
Java program to convert binary to decimal number using parseInt method
In this program, we will use parseInt method of Integer class to convert a binary number to decimal number.
static int parseInt(String s, int radix);
Above method of Integer class, parses the string argument as a signed integer in the radix specified by the second argument.
Above method of Integer class, parses the string argument as a signed integer in the radix specified by the second argument.
-
Arguments
- s : A number represented as a string.
- radix : Base(or Radix) of the input number used to convert String s into integer.
package com.tcc.java.programs;
import java.util.*;
public class BinaryToDecimal {
public static void main(String args[]) {
String binary;
Scanner in = new Scanner(System.in);
System.out.println("Enter a Binary Number");
binary = in.nextLine();
System.out.println("Decimal Number : "+Integer.parseInt(binary,2));
}
}
Output
Enter a Binary Number 1001 Decimal Number : 9
Java program to convert binary to decimal using while loop
Algorithm to convert Binary to Decimal number
- We multiply each binary digit with 2i and add them, where i is the position of the binary digit(starting from 0) from right side. Least significant digit is at position 0.
Let's convert 0101 binary number to decimal number
Decimal number = 0*23 + 1*22 + 0*21 + 1*20 = 0 + 4 + 0 + 1 = 5
package com.tcc.java.programs;
import java.util.*;
public class BinaryToDecimalTwo {
public static void main(String args[]) {
int num, decimal = 0, i=0;
Scanner in = new Scanner(System.in);
System.out.println("Enter a Binary Number");
String binary = in.nextLine();
num = Integer.parseInt(binary);
while(num != 0){
decimal += (num%10)*Math.pow(2, i);
num = num /10;
i++;
}
System.out.println("Decimal Number : "+ decimal);
}
}
Output
Enter a Binary Number 100 Decimal Number : 4
Enter a Binary Number 10101 Decimal Number : 21
Recommended Posts