modf()

The math.modf() function is a part of the Lua math library and is used to split a given number into its integral and fractional parts. It rounds the number down to the nearest integer and returns both the integer part and the fractional part as separate values.

Note: math.modf() rounds the number down and always returns a value equal to or less than the given number.

Syntax

As modf() is a method that is a part of the standard Lua math library, it must be called as math.modf().

integerPart, fractionalPart = math.modf(number)

math.modf() returns the integral part of number in integerPart and the fractional part in fractionalPart.

Example 1

To find the integral and fractional parts of a number:

local num = 5.3
local integerPart, fractionalPart = math.modf(num)
print("Integer part: " .. integerPart)
print("Fractional part: " .. fractionalPart)

This results in the following output:

Integer part: 5
Fractional part: 0.3

Example 2

When math.modf() is used with a number that is already an integer:

local num = 8
local integerPart, fractionalPart = math.modf(num)
print("Integer part: " .. integerPart)
print("Fractional part: " .. fractionalPart)

This results in the following output:

Output: Integer part: 8
Output: Fractional part: 0.0

Example 3

For negative numbers, math.modf() returns the closest integer greater than or equal to the given value:

local num = -3.3
local integerPart, fractionalPart = math.modf(num)
print("Integer part: " .. integerPart)
print("Fractional part: " .. fractionalPart)

This results in the following output:

Integer part: -3
Fractional part: -0.3