The Ruby **`lcm()` function** returns the LCM of two integers.

> The **LCM** or **least common multiple** is the smallest number that is the multiple of all the numbers used to calculate LCM.

Figure 1, below, shows the visual representation of the `lcm()` function.

# Syntax

```ruby
num_1.lcm(num_2)
# where num_1 and num_2 are the integers whose lcm is to be calculated
```

> If `num_1` or `num_2` or both are `non-integers`, then this function throws an `error`.

# Parameter

This function requires another integer, `(num_2)`, as a parameter.

# Return value

This function returns the LCM of two integers.

# Code

The following example shows how to use the `lcm()` function in Ruby.

# both positive numbers
print "(9).lcm(12) : ", (9).lcm(12), "\n"

# both negative numbers
print "(-24).lcm(-16) : ", (-24).lcm(-16), "\n"

# one of the numbers is zero
print "(0).lcm(12) : ", (0).lcm(12), "\n"

# one is negative and another is positive
print "(-9).lcm(18) : ", (-9).lcm(18), "\n"

What is lcm() in Ruby?

The Ruby lcm() function calculates the least common multiple of two integers.