Round a number to the nearest interval of a given number. (Because I always forget how darned simple this is.)

round-to-nearest.js

/**
 * Returns the number rounded to the nearest interval.
 * Example:
 * 
 *   roundToNearest(80, 100); // 100
 *   roundToNearest(25, 15);  // 30
 * 
 * @param {number} value    The number to round
 * @param {number} interval The numeric interval to round to
 * @return {number}
 */
function roundToNearest(value, interval) {
  return Math.round(value/interval) * interval;
}

when you input roundToNearest(86, 10); the result should be 90.
so the function should be
Math.round((value + interval/2)/interval) * interval;

when you input roundToNearest(86, 10); the result should be 90.
so the function should be
Math.round((value + interval/2)/interval) * interval;

No, this works as written. Your function incorrectly returns the following for inputs of 40 and 10: 50;