The number in a computer is expressed in binary, and the leftmost bit is generally used to indicate whether the number is positive or negative, so the number is a signed integer. If the leftmost bit is not used to represent positive or negative, but is connected with the following bits to represent an integer, then it is impossible to distinguish whether the number is positive or negative, and it can only be a positive number and an unsigned integer.

Extended data

Integers in computers are divided into two categories: unsigned integers (also called unsigned integers), which must be positive integers; Signed integer, which can represent positive and negative integers.

Unsigned integers are usually used to represent positive integers, such as addresses and indexes. They can be 8 bits, 16 bits, 32 bits, 64 bits or even more. The positive integer range of 8-bit binary number is 0-255, and the positive integer range of 16-bit binary number is 0-65535.

A byte is an 8-bit signed number. Because the first bit is used to represent symbols, only 7 bits can be used to represent numbers 000000 ~ 650438+0111,so it can also represent the range:-1/.

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