w3resource

JavaScript: Evaluate binomial coefficients

JavaScript Math: Exercise-20 with Solution

Write a JavaScript program to evaluate binomial coefficients.

Note:
Binomial coefficient : According to Wikipedia - In mathematics, binomial coefficients are a family of positive integers that occur as coefficients in the binomial theorem. They are indexed by two nonnegative integers; the binomial coefficient indexed by n and k is usually written \tbinom nk. It is the coefficient of the x k term in the polynomial expansion of the binomial power (1 + x) n. Under suitable circumstances the value of the coefficient is given by the expression :

Binomial coefficients

Arranging binomial coefficients into rows for successive values of n, and in which k ranges from 0 to n, gives a triangular array called Pascal's triangle.

Test Data:
console.log(binomial(8,3));
console.log(binomial(10,2));
Output :
56
45

Sample Solution:

JavaScript Code:

// Define a function named binomial that calculates the binomial coefficient "n choose k".
function binomial(n, k) {
    // Check if both n and k are of type number, if not, return false.
    if ((typeof n !== 'number') || (typeof k !== 'number')) 
        return false; 
    // Initialize the coefficient variable to 1.
    var coeff = 1;
    // Calculate the numerator of the binomial coefficient.
    for (var x = n - k + 1; x <= n; x++) coeff *= x;
    // Calculate the denominator of the binomial coefficient.
    for (x = 1; x <= k; x++) coeff /= x;
    // Return the calculated binomial coefficient.
    return coeff;
}

// Output the result of calculating the binomial coefficient "8 choose 3" to the console.
console.log(binomial(8, 3));
// Output the result of calculating the binomial coefficient "10 choose 2" to the console.
console.log(binomial(10, 2));

Output:

56
45

Flowchart:

Flowchart: JavaScript Math- Pythagorean function in JavaScript

Live Demo:

See the Pen javascript-math-exercise-20 by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus.

Previous: Create a Pythagorean function in JavaScript.
Next: Write a JavaScript function that Convert an integer into a Roman numeral.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://w3resource.com/javascript-exercises/javascript-math-exercise-20.php