An integer format is a data type in computer programming. Data is entered based on the type of information being stored, how precisely the numerical data is stored, and how that information will be handled in processing. Whole numbers represent whole units. Integers take up less memory space, but this space-saving feature limits the size of the integer that can be stored.
The entire format was developed to save memory on early computers.
Integers are whole numbers that are used in arithmetic, algebra, accounting, and enumeration applications. An integer implies that there are no smaller partial units. The number 2 as a whole number has a different meaning than the number 2.0. The second format indicates that there are two whole units and zero tenths of a unit, but that tenths of a unit are possible. The first number, as a whole number, implies that smaller units are not considered.
There are two reasons for an integer format in programming languages. First, an integer format is appropriate when considering objects that are not divisible into smaller units. A manager writing a computer program to calculate the division of a $100 bonus among three employees would not assign an integer format to the bonus variable, but instead would use one to store the number of employees. Programmers have recognized that integers are whole numbers and do not require that many digits to be represented accurately.
In the early days of computing, memory space was limited and valuable, and an integer format was developed to save memory. Since computer memory is a binary system, numbers have been represented in base 2, which means that the acceptable digits are 0 and 1. The number 10 in base 2 represents the number 2 in base 10, since 1 in column two is the digit multiplied by 2 raised to the second power. 100 in base 2 is equal to 8 in base 10, since 1 in the first column is 1 multiplied by 2 cubed.
Using an on/off basis to represent binary numbers, computers based on electricity were developed. A bit is a unique representation of on/off, true/false, or 0/1 data. Although different hardware configurations using variations of the number of bits the computer can directly address have been explored, the 8-bit byte and the 2-byte word have become standards for general-purpose computing. Therefore, specifying the width of the integer format does not determine the number of decimal places, but rather the largest and smallest value an integer can take.
The integer formats of most languages allow a bit to be used as a sign to designate a positive or negative integer. In a 32-bit language compiler, the C/C+ languages use the integer format, int, to store signed integer values between -231 and 231-1. An integer value is subtracted to make room for zero, or approximately +/- 2.1 trillion. On a 64-bit compiler, with the int64 data type, signed integer values between -263 and 263-1 or +/- 9.2 quintillion are allowed.
