w3resource

JavaScript: Maximum value swapping two digits in an integer

JavaScript Math: Exercise-112 with Solution

Write a JavaScript program to calculate the maximum value by swapping two digits in a given integer.

Test Data:
(100) -> 100
(120) -> 210
(129) -> 921

Sample Solution:

JavaScript Code:

/**
 * Function to find the maximum value by swapping two digits in the given integer.
 * @param {number} n - The integer.
 * @returns {number} - The maximum value obtained after swapping two digits, if any.
 */
function test(n) {
    // Convert the integer to a string
    var n_str = n.toString();
    
    // Loop through each digit of the integer
    for (var i = 0; i < n_str.length; i++) {
        var t = n_str[i]; // Current digit
        var index = i; // Index of the current digit
            
        // Find the maximum digit greater than the current digit
        for (var x = n_str.length - 1; x > i; x--) {
            if (n_str[x] > t) {
                t = n_str[x];
                index = x;
            }
        }
        
        // If a greater digit is found, swap the digits and return the new integer
        if (t != n_str[i]) {
            var nums = n_str.split('');
            
            var tmp = nums[i];
            
            nums[i] = nums[index];
            nums[index] = tmp;
            
            return parseInt(nums.join(''));
        }
    }
    // If no swap is possible, return the original integer
    return n;
}

// Test cases
n = 100;
console.log("n = " + n);
console.log("Maximum value swapping two digits in the said integer: " + test(n));
n = 120;
console.log("n = " + n);
console.log("Maximum value swapping two digits in the said integer: " + test(n));
n = 129;
console.log("Maximum value swapping two digits in the said integer: " + test(n));
console.log("e: " + test(n));

Output:

n = 100
Maximum value swapping two digits in the said integer: 100
n = 120
Maximum value swapping two digits in the said integer: 210
Maximum value swapping two digits in the said integer: 921
e: 921

Flowchart:

JavaScript: Maximum value swapping two digits in an integer.

Live Demo:

See the Pen javascript-math-exercise-112 by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus.

Previous: Kth smallest number in a multiplication table.
Next: Smallest number whose digits multiply to a number.

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://www.w3resource.com/javascript-exercises/javascript-math-exercise-112.php