Integer data is numerical data with no decimal part, which is represented by the letter I. Integer data is only used to represent integers and is stored in binary form. There are four types of integer variables: byte, short, integer and long. The following table lists the number of bits in each type of memory and their ranges. Int type is the most commonly used integer type. The data range it represents is large enough for 32-bit and 64-bit processors. However, for large-scale calculation, large integers are often encountered, which are beyond the range represented by int types. At this time, the long type will be used.