What is the range of a 32-bit signed integer?

From - 2147483647 to 2147483648.

Explanation:

A 32 bit integer has 2^32 = 4294967296 possible values. A signed integer has positive and negative values as well as the zero.

Of these values (2^32) / 2 will be positive, (2^32) / 2 - 1 will be negative and one will be the zero.

Therefore the range is from - (2^32) / 2 + 1 to (2^32) / 2.

This can also be expressed as from - 2147483647 to 2147483648.