JavaScript: Evaluate binomial coefficients

Last update on August 19 2022 21:50:50 (UTC/GMT +8 hours)

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 :

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:-

HTML Code:

<!DOCTYPE html>
  <html>
  <head>
  <meta charset="utf-8">
  <title>Binomial coefficient</title>
  </head>
  <body>
</body>
  </html>

JavaScript Code:

function binomial(n, k) {
     if ((typeof n !== 'number') || (typeof k !== 'number')) 
  return false; 
    var coeff = 1;
    for (var x = n-k+1; x <= n; x++) coeff *= x;
    for (x = 1; x <= k; x++) coeff /= x;
    return coeff;
}

console.log(binomial(8,3));
console.log(binomial(10,2));

Sample Output:

56
45

Flowchar:

$Flowchart: JavaScript Math- Pythagorean function in JavaScript$

Live Demo:

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

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