Question

Could anyone please tell me how to convert the unsigned char ‘0’ to a byte in Java ?

Thank you

Answer 1

You can covert it two ways depending on what you are trying to do

char ch = '0';
byte b = (byte) ch; // ASCII value of '0'

or

byte b = (byte) (ch - '0'); // numeric value of 0

or

byte b = (byte) Character.getNumericValue(ch); // numeric value.

The last one is interesting because it gives you the numeric value of all characters, not just ‘0’ .. ‘9’

for (int ch = Character.MIN_VALUE; ch < Character.MAX_VALUE; ch++) {
    int value = Character.getNumericValue(ch);
    if (value > 99)
        System.out.println("The numeric value for " + (char) ch + " is " + value);
}

prints

The numeric value for ௱ is 100
The numeric value for ௲ is 1000
The numeric value for ፻ is 100
The numeric value for ፼ is 10000
The numeric value for Ⅽ is 100
The numeric value for Ⅾ is 500
The numeric value for Ⅿ is 1000
The numeric value for ⅽ is 100
The numeric value for ⅾ is 500
The numeric value for ⅿ is 1000
The numeric value for ↀ is 1000
The numeric value for ↁ is 5000
The numeric value for ↂ is 10000