JavaScript: Find the maximum integer n

JavaScript Basic: Exercise-145 with Solution

Write a JavaScript program to find the maximum integer n such that 1 + 2 + ... + n <= a given integer.

Sample Solution:

JavaScript Code:

/**
 * Function to find the sum of natural numbers up to a given value
 * @param {number} val - The value up to which the sum of natural numbers needs to be calculated
 * @returns {number} - The number of terms in the sum sequence
 */
function sumn(val) {
  var sn = 0; // Initialize the sum of natural numbers
  var i = 0; // Initialize the index to 0
  
  // Loop to calculate the sum of natural numbers up to a certain limit
  while (sn <= val) {
    sn += i++; // Incrementally add the value of 'i' to the sum and increment 'i'
  }
  
  return i - 2; // Return the number of terms in the sum sequence (subtracting 2 to account for the extra iteration)
}

// Display the number of terms for different values
console.log(sumn(11)); // Output: 4
console.log(sumn(15)); // Output: 5 

Output:

4
5

Live Demo:

See the Pen javascript-basic-exercise-145 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

/**
 * Function to find the sum of natural numbers up to a given value
 * @param {number} val - The value up to which the sum of natural numbers needs to be calculated
 * @returns {number} - The number of terms in the sum sequence
 */
const sumn = (val) => {
  let sn = 0; // Initialize the sum of natural numbers
  let i = 0; // Initialize the index to 0
  
  // Loop to calculate the sum of natural numbers up to a certain limit
  while (sn <= val) {
    sn += i++; // Incrementally add the value of 'i' to the sum and increment 'i'
  }
  
  return i - 2; // Return the number of terms in the sum sequence (subtracting 2 to account for the extra iteration)
};

// Display the number of terms for different values
console.log(sumn(11)); // Output: 4
console.log(sumn(15)); // Output: 5

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