For example:

Char type is adopted, and a non-negative integer is represented by one byte. The minimum value is 0, and the maximum value cannot be 128.

Character type range:-128~ 127.

The range of unsigned character types is 0~255.

Extended data:

The char type accounts for 1 byte, which is 8 bits, and the storable positive integer is 01111,which is 127. If the int integer i= 128 is given to ch, overflow will occur.

Because 128 is an int type, accounting for 4 bytes, the binary code is 0000 0000 0000 00001000 0000. If assigned to a char variable with only 8 bits, only the lower 8 bits of 1000 0000 can be put in, and the rest will be deleted.

Integers are stored in the form of complement in the computer. At this time, 1000000 is a complement in the eyes of the computer, and the leftmost one is 1, indicating a negative number. Complement 1000000 corresponds to decimal system-128, so the final output is-128. So overflow will make the largest positive integer become the smallest negative integer.