JavaScript: Least common multiple (LCM) of more than 2 integers

JavaScript Math: Exercise-11 with Solution

LCM of Multiple Numbers

Write a JavaScript function to get the least common multiple (LCM) of more than 2 integers.

Test Data :
console.log(lcm_more_than_two_numbers([100,90,80,7]));
console.log(lcm_more_than_two_numbers([5,10,15,25]));
Output :
25200
150

Sample Solution:

JavaScript Code:

// Define a function named lcm_more_than_two_numbers that calculates the least common multiple (LCM) of an array of numbers.
function lcm_more_than_two_numbers(input_array) {
    // Check if the input is an array, if not, return false.
    if (toString.call(input_array) !== "[object Array]")  
        return false;  
    
    var r1 = 0, r2 = 0;
    // Get the length of the input array.
    var l = input_array.length;
    // Iterate through the input array to calculate the LCM.
    for(i = 0; i < l; i++) {
        // Calculate the remainder when dividing the current element by the next element.
        r1 = input_array[i] % input_array[i + 1];
        // If the remainder is 0, update the next element to the product of the current element and the next element divided by the next element.
        if (r1 === 0) {
            input_array[i + 1] = (input_array[i] * input_array[i + 1]) / input_array[i + 1];
        }
        // If the remainder is not 0, calculate the remainder when dividing the next element by the previous remainder.
        else {
            r2 = input_array[i + 1] % r1;
            // If the new remainder is 0, update the next element to the product of the current element and the next element divided by the previous remainder.
            if (r2 === 0) {
                input_array[i + 1] = (input_array[i] * input_array[i + 1]) / r1;
            }
            // If the new remainder is not 0, update the next element to the product of the current element and the next element divided by the new remainder.
            else {
                input_array[i + 1] = (input_array[i] * input_array[i + 1]) / r2;
            }
        }
    }
    // Return the last element of the modified input array, which represents the LCM.
    return input_array[l - 1];
}

// Output the LCM of the numbers 100, 90, 80, and 7 to the console.
console.log(lcm_more_than_two_numbers([100, 90, 80, 7])); 
// Output the LCM of the numbers 5, 10, 15, and 25 to the console.
console.log(lcm_more_than_two_numbers([5, 10, 15, 25]));

Output:

25200
150

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-11 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that calculates the LCM of an array of numbers by successively computing the LCM of pairs.
• Write a JavaScript function that uses the reduce() method to compute the LCM of multiple numbers.
• Write a JavaScript function that validates input before computing the LCM of several numbers.
• Write a JavaScript function that returns a detailed string showing how the LCM was computed for an array of numbers.

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