The Least Common Multiple (**LCM**) of two integers is the smallest positive integer that is perfectly divisible by both integers.

For example, the LCM of **6** and **8** is **24**.

## Example 1: LCM Using while Loop and if Statement

```
// program to find the LCM of two integers
// take input
const num1 = prompt('Enter a first positive integer: ');
const num2 = prompt('Enter a second positive integer: ');
// higher number among number1 and number2 is stored in min
let min = (num1 > num2) ? num1 : num2;
// while loop
while (true) {
if (min % num1 == 0 && min % num2 == 0) {
console.log(`The LCM of ${num1} and ${num2} is ${min}`);
break;
}
min++;
}
```

**Output**

Enter a first positive integer: 6 Enter a second positive integer: 8 The LCM of 6 and 8 is 24

In the above program, the user is prompted to enter two positive integers.

The greater number among the numbers provided by the user is stored in a `min` variable. The LCM of two numbers cannot be less than the greater number.

The while loop is used with an `if`

statement. In each iteration,

- The variable
`min`

is divided by both the`num1`and`num2`. - If both numbers' remainders are equal to
**0**, then it is the LCM and the break statement terminates the program. - If both numbers' remainders are not equal to
**0**, the value of`min`is increased by**1**and the loop continues. - The
`while`

loop continues until the condition is met.`if (min % num1 == 0 && min % num2 == 0)`

The LCM of two numbers can also be found using the formula:

LCM = (num1*num2) / HCF

To learn about how to find the HCF, visit the JavaScript program to find HCF.

## Example 2: LCM Calculation Using HCF

```
// program to find the LCM of two integers
let hcf;
// take input
const number1 = prompt('Enter a first positive integer: ');
const number2 = prompt('Enter a second positive integer: ');
// looping from 1 to number1 and number2 to find HCF
for (let i = 1; i <= number1 && i <= number2; i++) {
// check if is factor of both integers
if( number1 % i == 0 && number2 % i == 0) {
hcf = i;
}
}
// find LCM
let lcm = (number1 * number2) / hcf;
// display the hcf
console.log(`HCF of ${number1} and ${number2} is ${lcm}.`);
```

**Output**

Enter a first positive integer: 6 Enter a second positive integer: 8 The LCM of 6 and 8 is 24.

In the above program, firstly HCF of the numbers is calculated. Then LCM is calculated using the given formula.