Even simple arithmetic with small,This is not true in Java 1.1 and later.byte-valued constants as follows produces "Explicit cast needed to convert int to byte" errors:
byte b = 1 + 2;
p. 9: In the middle of the page, the arithmetic algorithm given for finding the last byte of the number is incorrect for negative numbers. That section should read like this:
This is the effect of taking the remainder modulo 256 of the int b and adding 256 if the value is negative; that is,p. 10: In the line of code near the top of the page the greater than sign should be greater than or equals; that is,
b = b % 256 >= 0 ? b % 256 : 256 + b % 256;More simply, using bitwise operators,
b = b & 0x000000FF;
int unsignedByte = signedByte >= 0 ? signedByte : 256 + signedByte;
p. 13: EBCDIC is more often an eight-bit character set than a seven-bit set (but only IBM knows for sure in all the different versions of EBCDIC that exist)
p. 15:
In Java 1.1 and later, compilers can figure out if an operation performed on
char literals (though not char variables)
will overflow the bounds of a char. Thus change the
the paragraph beginning, "A char used in arithmetic..."
and the following code fragment and paragraph to:
A char used in arithmetic is promoted to int. This presents the same problems as it does for bytes. Admittedly, performing mathematical operations on chars is a much less common thing to want to do than performing them on bytes.
p. 21: In the second paragraph of the System.out section change
"Hello World" to "Hello World!"
p. 23: In the first paragraph on the page, change
For example, if the user types "Hello World", the following bytes will be read from System.in in this order:to
For example, if the user types "Hello World!" and hits the return or enter key, the following bytes will be read from System.in in this order: