String to byte Conversion: Sometimes, we obtain the values in string format in Java. Printing the value is no problem (as long as user gets the same output) as it prints the same value as data type prints.
For example, a byte value is obtained in string format as in command-line arguments or from TextField's getText() method. The string value is to be converted into byte format to use in caluclations as strings (or any objects in Java) cannnot be multiplied or used in any arithmetic operation. To convert, casting does not work as string and byte are incompatable for conversion either implicitly or explicitly. It requires extra effort in coding known as "parsing operation". Parsing operation involves the usage of a wrapper class and parseXXX() method. For string to byte conversion, it is required Byte class and parseByte() method and explained in the following program.
Parsing Example on String to byte
public class Conversions
public static void main(String args)
String str = "10";
System.out.println("10 in String form: " + str); // printing is no problem, but str * str throws error
byte b1 = Byte.parseByte(str); // String to byte conversion. Parsing operation
System.out.println("10 in byte form: " + b1);
System.out.println("Square of byte 10: " + b1 * b1); // using in multiplication
Output screenshot on String to byte Example
parseByte() is a method of wrapper class Byte which converts string str to byte b1. Now b1 can be used in arithmetic operations.
Using the same technique, it is possible to convert string to other data types short, int, long, float, double, character and boolean.
Note: The other way byte to string is also possible.