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 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. 