Convert String to ASCII in Java

Java is a powerful programming language that provides developers with a lot of built-in functionality. One of the features that Java provides is the ability to convert a string to ASCII. This process can be useful when dealing with data that needs to be transmitted or stored in a way that only accepts ASCII characters. In this article, we will explore how to convert a string to ASCII in Java.

ASCII stands for American Standard Code for Information Interchange. It is a character encoding standard that assigns unique numeric values to 128 different characters, including letters, numbers, and symbols. These values range from 0 to 127 and are represented as 7-bit binary numbers.

To convert a string to ASCII in Java, we can use the getBytes() method. This method is a part of the String class and returns an array of bytes representing the characters of the string using the specified encoding.

Here is an example of how to convert a string to ASCII in Java:

String str = "Hello, World!";
byte[] ascii = str.getBytes("US-ASCII");

In this example, we create a string variable named "str" that contains the text "Hello, World!". We then use the getBytes() method to convert this string to ASCII and store the result in a byte array named "ascii". We specify the encoding as "US-ASCII", which is the standard ASCII encoding used in the United States.

We can also use the ASCII encoding to convert individual characters to their ASCII values. To do this, we can use the charAt() method to retrieve the character at a specific position in the string and then convert it to its ASCII value using the (int) cast.

Here is an example of how to convert a character to its ASCII value in Java:

char c = 'A';
int asciiValue = (int) c;

In this example, we create a char variable named "c" that contains the letter "A". We then use the (int) cast to convert this character to its ASCII value and store the result in an integer variable named "asciiValue".

In addition to the methods discussed in the previous section, there are several other ways to convert a string to ASCII in Java. Let's explore some of these methods below:

1. Using a loop to iterate through each character of the string:

String str = "Hello, World!";
StringBuilder asciiBuilder = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
    char c = str.charAt(i);
    int asciiValue = (int) c;
    asciiBuilder.append(asciiValue);
}


String asciiString = asciiBuilder.toString();

In this example, we create a StringBuilder object named "asciiBuilder" to store the ASCII values of each character in the string. We use a loop to iterate through each character of the string and convert it to its ASCII value using the (int) cast. We then append the ASCII value to the StringBuilder object. Finally, we convert the StringBuilder object to a string using the toString() method and store the result in a variable named "asciiString".

2. Using the Apache Commons Lang library:

The Apache Commons Lang library provides a utility class named "StringUtils" that contains a method named "toAsciiString". This method takes a string as input and returns a string containing the ASCII representation of each character in the input string.

String str = "Hello, World!";
String asciiString = StringUtils.toAsciiString(str);

In this example, we create a string variable named "str" that contains the text "Hello, World!". We then use the toAsciiString() method from the StringUtils class to convert this string to its ASCII representation and store the result in a variable named "asciiString".

Filename: Conversion.java

import org.apache.commons.lang3.ArrayUtils;


public class Conversion {
    public static void main(String[] args) {
        String inputString = "Hello, World!";


        byte[] asciiValues = inputString.getBytes();


        System.out.println("Input String: " + inputString);
        System.out.print("ASCII values: ");
        for (byte ascii : asciiValues) {
            System.out.print(ascii + " ");
        }


        // Alternatively, you can use the ArrayUtils class from Apache Commons Lang
        int[] asciiValuesArrayUtils = ArrayUtils.toPrimitive(ArrayUtils.toObject(asciiValues));
        System.out.print("\nASCII values (using ArrayUtils): ");
        for (int ascii : asciiValuesArrayUtils) {
            System.out.print(ascii + " ");
        }
    }
}

Output:

Input String: Hello, World!
ASCII values: 72 101 108 108 111 44 32 87 111 114 108 100 33 
ASCII values (using ArrayUtils): 72 101 108 108 111 44 32 87 111 114 108 100 33

3. Using the Guava library:

The Guava library provides a utility class named "Ascii" that contains several methods for working with ASCII characters. One of these methods is "toAsciiString", which takes a string as input and returns a string containing the ASCII representation of each character in the input string.

String str = "Hello, World!";
String asciiString = Ascii.toAsciiString(str);

In this example, we create a string variable named "str" that contains the text "Hello, World!". We then use the toAsciiString() method from the Ascii class to convert this string to its ASCII representation and store the result in a variable named "asciiString".

Filename: Conversion2.java

import com.google.common.primitives.Bytes;
import com.google.common.primitives.Ints;
public class Conversion2 {
    public static void main(String[] args) {
        String inputString = "Hello, World!";


        byte[] asciiValues = inputString.getBytes();


        System.out.println("Input String: " + inputString);
        System.out.print("ASCII values: ");
        for (byte ascii : asciiValues) {
            System.out.print(ascii + " ");
        }


        // Alternatively, you can use the Bytes and Ints classes from Guava
        int[] asciiValuesGuava = Ints.toArray(Bytes.asList(asciiValues));
        System.out.print("\nASCII values (using Guava): ");
        for (int ascii : asciiValuesGuava) {
            System.out.print(ascii + " ");
        }
    }
}

Output:

Input String: Hello, World!
ASCII values: 72 101 108 108 111 44 32 87 111 114 108 100 33 
ASCII values (using Guava): 72 101 108 108 111 44 32 87 111 114 108 100 33

In conclusion, there are several ways to convert a string to ASCII in Java, including using a loop to iterate through each character of the string, using the Apache Commons Lang library, and using the Guava library. Depending on your specific use case, one method may be more appropriate than another. It is important to choose the method that best fits your needs and to thoroughly test your code to ensure that it is functioning as expected.