Binary and decimal are two numeral systems used to represent numbers. Binary is a base-2 numeral system, meaning it uses only two digits, 0 and 1, to represent any number. Decimal is a base-10 numeral system that uses ten digits, 0 to 9, to represent numbers.
In programming, it is common to need to convert between different numeral systems, especially when dealing with binary data or manipulating bits. Java is a popular language which gives many methods to convert binary to decimal.
In this article we will study about how to convert binary to decimal in java. We will also highlight some common pitfalls to avoid when converting binary to decimal in Java.
Why is there a need for Convert binary to decimal in Java
In Java, this conversion can be done using built-in functions and algorithms. Here are a few reasons why the conversion of binary to decimal is needed in Java.
- Representing Large Numbers: One of the primary reasons for using binary to decimal conversion is to represent large numbers that cannot be efficiently represented in binary format. Binary numbers require more digits to represent the same value as a decimal number. Therefore, it is much easier to work with large numbers in decimal format.
- Showing data: Binary data needs to be shown in a human-readable format. Such as, the binary data stored in a file may need to be displayed in a text format. In such cases, converting binary data to decimal format allows for easy display of the data.
- Mathematical Operations: It is easier to work with decimal numbers than binary numbers. Addition, subtraction, multiplication, can be done with help of some operations. However, performing these operations on binary numbers requires more complex algorithms. Therefore, converting binary numbers to decimal numbers before performing mathematical operations simplifies the process.
- Debugging: Converting binary data to decimal format can also be useful for debugging purposes. It may be necessary to check the binary data stored in memory or in a file. It makes the data easy to read. This helps to find errors or bugs in the code that may be causing big problems.
- Networking: In networking, binary data is often used to represent messages or data packets. However, the data needs to be converted to decimal format for display or storage purposes. For example, IP addresses are represented in binary format but are usually displayed in decimal format. Therefore, converting binary data to decimal format is necessary for proper communication and interpretation of network data.
Different Approach for how to convert binary to decimal in java
Here are some of the different approaches that how to convert binary to decimal in Java:
- Method 1: Using Integer.parseInt() method
- Method 2: Using Math.pow() method
- Method 3: Using Bitwise Operators
Different methods for how to convert from binary to decimal in Java
Method 1: Using Integer.parseInt() method
The easiest way to convert a binary string to decimal is Integer.parseInt() method in Java. This method takes two arguments – the binary string and the radix (base) of the input number.
public class Now {
// main method
public static void main(String args[])
{
String binaryNumber = "101010";
int decimalNumber = Integer.parseInt(binaryNumber, 2);
System.out.println("Decimal equivalent of " + binaryNumber + " is: " + decimalNumber);
}
}Output:
Decimal equivalent of 101010 is: 42Explanation:
- Declare a String variable to store the binary number that needs to be converted to decimal.
- The first variable is the String, which represents the binary number, and the second variable is the radix.
- The Integer.parseInt() method returns int value which shows the decimal equivalent of the binary number. Assign this value to a new variable (in this case, decimalNumber) for further use.
- You can then print out the decimal number to the console or use it in any further calculations.
Method 2: Using Math.pow() method
Another way to convert a binary number to decimal is Math.pow() method. This method takes two arguments – the base and the exponent. We can use this method to calculate the decimal equivalent of each bit in the binary number, and then add them to get the final decimal value.
class test{
public static void main(String[] args) {
// Step 1: Declare and initialize binary number
String binary = "1010";
// Step 2: Convert binary to decimal using Math.pow()
int decimal2 = 0;
int position = 0;
for (int i = binary.length() - 1; i >= 0; i--) {
int digit = binary.charAt(i) - '0'; // convert char to int
decimal2 += digit * Math.pow(2, position); // add to decimal
position++; // increment position
}
System.out.println("Decimal equivalent of " + binary + " is " + decimal2);
}
}Output:
Decimal equivalent of 1010 is 10Explanation:
- Declare and initialize a string variable with the binary number you want to convert.
- You can also use the Math.pow() method to manually convert the binary number to decimal. This method takes two arguments, the base and the exponent, and returns the result of the base raised to the exponent.
- In this case, we will use a loop to iterate through each digit of the binary number, starting from the rightmost digit (least significant bit), and calculate the decimal equivalent by adding 2 raised to the power of the digit position multiplied by the binary digit value (0 or 1).
Method 3: Using bitwise operations
We can also convert a binary number to decimal using bitwise operations in Java. We can start by initializing a decimal variable to 0, and then use a loop to iterate through each bit in the binary number. We can use the left shift operator (<<) to shift the decimal number by 1 bit to the left, and then add the value of the current bit to the decimal number using the bitwise OR operator (|).
//how to convert binary to decimal Using bitwise operations
import java.util.Scanner;
//how to convert binary to decimal Using bitwise operations
class test{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a binary number: ");
String binary = sc.nextLine();
int decimal = 0;
int power = 0;
for (int i = binary.length() - 1; i >= 0; i--) {
if (binary.charAt(i) == '1') {
decimal += 1 << power;
}
power++;
}
System.out.println("Decimal equivalent: " + decimal);
}
}Output:
//let Enter binary number is 1011011
Decimal equivalent: 91
Explanation:
- Create a variable to store the decimal value and initialize it to 0.
- Get the binary number as input from the user or define it as a string.
- Convert the binary string to an integer using the parseInt() method.
- Use bitwise operators such as shift right (>>) and bitwise AND (&) to extract each bit from the binary number and calculate the decimal equivalent.
- Add the calculated decimal value to the variable created in Step 1.
- Repeat Steps 4-5 for each bit in the binary number.
- Print the final decimal value.
Best Approach for convert binary to decimal in java
The Integer.parseInt() method in Java is commonly used to convert a string representation of an integer into an actual integer value.
Here are some reasons why Integer.parseInt() is a good method to convert binary to decimal in Java:
- It’s easy to use: Integer.parseInt() is a simple and easy-to-use method that can quickly and easily convert binary into decimal in java.
- It’s built-in: Integer.parseInt() is a built-in method in Java, which means you don’t need to create your own conversion method or import any external libraries to use it.
- It’s efficient: Integer.parseInt() is an optimized method that uses the Java Virtual Machine’s built-in binary-to-decimal conversion algorithm, which is designed to be fast and efficient.
- It handles error checking: Integer.parseInt() also handles error checking for you, ensuring that the input is a valid binary string before attempting the conversion. If the input is not a valid binary string, Integer.parseInt() will throw a NumberFormatException.
Sample Problem for Converting Binary to decimal in java
Sample Problem 1:
Suppose you are making an assignment where users enter their roll number. The roll number is stored as a binary number in a database, and you need to convert it to a decimal to understand.
Solution:
- We first prompt the user to enter a binary number.
- We use the Scanner class to read the input from the user.
- We then use the Integer.parseInt() method to convert the binary number to a decimal number. The first parameter of the method is the binary number, and the second parameter is the radix, which is set to 2 to indicate that the input is a binary number.
- Finally, we display the decimal equivalent of the binary number using the System.out.println() method.
Solution Code:
import java.util.Scanner;
public class BinaryToDecimal {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter your roll number :");
String binary = sc.next();
int decimal = Integer.parseInt(binary, 2);
System.out.println("Decimal : " + decimal);
}
}
Output
Enter your roll number number: 101000110011
Decimal : 2611
Sample Problem 2:
Suppose you are doing a total of 2 numbers and these two numbers are in binary you need to convert it to a decimal to understand.
Solution:
- In this code, we first define two binary numbers num1 and num2 using the 0b prefix to indicate that they are binary numbers. We then define two variables decimal1 and decimal2 to store the decimal representations of the binary numbers.
- We use a while loop to iterate over each bit in the binary numbers. In each iteration, we use the bitwise AND operator & with the value 1 to extract the least significant bit of the binary number.
- We then shift this bit to the correct position using the left shift operator << and add it to the decimal variable.
- Finally, we shift the binary number to the right by one position using the unsigned right shift operator >>> to discard the least significant bit.
- After converting the binary numbers to decimal, we use the Integer.toBinaryString() method to print out the binary representation of the numbers, along with their decimal representations.
public class BinaryToDecimal {
public static void main(String[] args) {
int num1 = 0b1101; // binary representation of 13
int num2 = 0b1010; // binary representation of 10
int decimal1 = 0;
int decimal2 = 0;
int bitPosition = 0;
while (num1 != 0) {
decimal1 += (num1 & 1) << bitPosition;
bitPosition++;
num1 >>>= 1;
}
bitPosition = 0;
while (num2 != 0) {
decimal2 += (num2 & 1) << bitPosition;
bitPosition++;
num2 >>>= 1;
}
System.out.println("Binary 1: " + Integer.toBinaryString(0b1101));
System.out.println("Decimal 1: " + decimal1);
System.out.println("Binary 2: " + Integer.toBinaryString(0b1010));
System.out.println("Decimal 2: " + decimal2);
}
}Output:
Binary 1: 1101
Decimal 1: 13
Binary 2: 1010
Decimal 2: 10
Sample Problem 3:
Suppose you are calculating a percentage of 1000110 out of 500 and numbers are in binary you need to convert it to a decimal.
Solution:
- We start by defining the binary number as a string variable named binary.
- We also initialize two integer variables, decimal and power, to 0. decimal will store the decimal equivalent of the binary number, and power will keep track of the power of 2 to be used in the conversion.
- We then loop through the binary number from right to left, starting from the least significant bit (i.e., the one’s place). For each bit, we check if it is a 1. If it is, we add 2 to the power of the position of the bit (i.e., 2^0 for the least significant bit, 2^1 for the next, and so on) to decimal. We also increment power to move on to the next bit.
- Once the loop is complete, decimal will contain the decimal equivalent of binary.
- We calculate the percentage by dividing decimal by 500 (converted to a double to ensure decimal division), multiplying by 100, and storing the result in a percentage variable.
- Finally, we print out the binary number in decimal form, as well as the percentage out of 500.
public class BinaryToDecimal {
public static void main(String[] args) {
String binary = "1000110";
int decimal = 0;
int power = 0;
for (int i = binary.length() - 1; i >= 0; i--) {
if (binary.charAt(i) == '1') {
decimal += Math.pow(2, power);
}
power++;
}
double percentage = (decimal / 500.0) * 100;
System.out.println("Binary " + binary + " in decimal is " + decimal);
System.out.println(decimal + " out of 500 is " + percentage + "%");
}
}
Output:
Binary 1000110 in decimal is 70
70 out of 500 is 14.0%
Conclusion
Converting binary to decimal in Java can be done by using various methods. The simplest method is Integer.parseInt() function, which takes a binary string as input and returns its decimal equivalent.
Another method is to implement a custom algorithm that iterates over each binary digit and calculates its decimal equivalent using powers of 2. Both methods are simple and easy in Java.
Therefore, conversion of binary into decimal is a matter of understanding the relationship between the two systems and applying the appropriate conversion algorithm.
With the right approach, converting binary to decimal in Java can be a simple and efficient task. I hope you will get to know about how to convert from binary to decimal in java.
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