-1 will always convert to the max unsigned value, this is due to section 4.7 Integral conversions: If the destination type is unsigned, the resulting value is the least unsigned integer congruent to the source integer (modulo 2n where n is the number of bits used to represent the unsigned type). [ Note: In a … Read more
It’s done so that addition doesn’t need to have any special logic for dealing with negative numbers. Check out the article on Wikipedia. Say you have two numbers, 2 and -1. In your “intuitive” way of representing numbers, they would be 0010 and 1001, respectively (I’m sticking to 4 bits for size). In the two’s … Read more
Two’s complement subtracts off (1<<bits) if the highest bit is 1. Taking 8 bits for example, this gives a range of 127 to -128. A function for two’s complement of an int… def twos_comp(val, bits): “””compute the 2’s complement of int value val””” if (val & (1 << (bits – 1))) != 0: # if … Read more
Let’s start by summarizing Java primitive data types: byte: Byte data type is an 8-bit signed two’s complement integer. Short: Short data type is a 16-bit signed two’s complement integer. int: Int data type is a 32-bit signed two’s complement integer. long: Long data type is a 64-bit signed two’s complement integer. float: Float data … Read more
Two’s complement is a clever way of storing integers so that common math problems are very simple to implement. To understand, you have to think of the numbers in binary. It basically says, for zero, use all 0’s. for positive integers, start counting up, with a maximum of 2(number of bits – 1)-1. for negative … Read more