Integer
In mathematics, integers are whole numbers (natural numbers, their negatives and zero).[1] Integers can also be shown on a number line like this:
[math]\displaystyle{ {...-4, -3, -2, -1, 0, +1, +2, +3, +4,...}\,\! }[/math]
In particular, zero or 0 is an integer that is neither positive nor negative. An integer is a whole number with no fractional or decimal part.
Integers have no smallest or largest value because for any given integer, there is always a larger and smaller integer. Any integer is either greater than or smaller than any other integer. Consecutive integers are integers that come after each other (as in [math]\displaystyle{ {1, 2, 3, 4} }[/math]).
The sum, difference and product of integers is always an integer.(for example, (12 + 2345 × (67 - 8)) × 9 is an integer). An integer divided by an integer is sometimes not an integer (for example, 1 ÷ 2 = 0.5).
[math]\displaystyle{ \mathbf{Z} }[/math] or [math]\displaystyle{ \mathbb{Z} }[/math] is the name of the set of integers, and [math]\displaystyle{ \mathbb{Z}_+\! }[/math] is the set of positive integers.[2][3] ([math]\displaystyle{ \mathbf{Z} }[/math], +, 0) is an abelian group.
The number of integers is infinite. The cardinal number of [math]\displaystyle{ \mathbf{Z} }[/math] is [math]\displaystyle{ \aleph_0 }[/math]. The ordinal number of [math]\displaystyle{ \mathbf{Z} }[/math] is [math]\displaystyle{ ^*\omega + \omega }[/math].
To sum up, an integer is a whole number that has no decimals.
In programming
In some programming languages, like C, there are types called "int" or "integer."
Integer Media
Integers can be thought of as discrete, equally spaced points on an infinitely long number line. In the above, non-negative integers are shown in blue and negative integers in red.
A figure representing the equivalence classes of the relative numbers constructed as a pair of natural numbers. Any relative number (eg. -5) has an infinity of equivalent possible representation, eg. (2,7), (0,5), … The equivalent representations (in red) are on the same blue dotted line, and the number in blue at the end on the line is the corresponding relative number
Notes
- ↑ Negative numbers have a minus (−) in front of the number. Positive numbers have no sign or a plus (+) sign in front. Zero usually has no sign.
- ↑ "Comprehensive List of Algebra Symbols". Math Vault. 2020-03-25. Retrieved 2020-08-11.
- ↑ Weisstein, Eric W. "Integer". mathworld.wolfram.com. Retrieved 2020-08-11.