Optimal verification if a number is Palindrom in JS

palindrome number javascript w3schools
palindrome in javascript in w3schools
palindrome number in javascript
program to find palindrome using javascript
palindrome string program in html using javascript
palindrome program in javascript w3schools
palindrome in javascript using for loop
javascript palindrome stack overflow

I have a problem I am sitting on for the past few days.

I want to write an optimal (in JS) program for verifying if a number is a Palindrome.

My current approach:

function isPalidrom2(pali){
//MOST time consuming call - I am splitting the digit into char array. 
  var digits = (""+pali).split("");
//To get the length of it. 
  var size = digits.length;
  var isPali = true;
  for(var i = 0; i<Math.floor(size/2); i++){
    //I am comparing digits (first vs last, second vs last-1, etc.) one by one, if ANY of the pars is not correct I am breaking the loop. 
    if(parseInt(digits[i]) != parseInt(digits[size-i-1])){
      isPali = false;
      break;
    }
  }
  return isPali;
}

To keep the spirit of you code, you could exit the loop with return instead of break and use the string directly without converting to an array. Strings have, as arrays, the possibility of an access single character with an index.

function isPalidrom2(value) {
    var digits = value.toString(),
        length = digits.length,
        i, l;

    for (i = 0, l = length >> 1; i < l; i++) {
        if (digits[i] !== digits[length - i - 1]) {
            return false;
       }
    }
    return true;
}

console.log(isPalidrom2(1));
console.log(isPalidrom2(12));
console.log(isPalidrom2(1221));
console.log(isPalidrom2(123));

Check number is palindrome or not in JavaScript, . For example: 12321 after rotation 12321number is still same. Guide to Palindrome in JavaScript. Here we discuss the introduction and logical explanation with an example to check if the string/number is a palindrome.


The fastest is probably to rely on javascripts native methods:

 function isPalindrome(str) {
   const lower = str.substr(0, Math.floor(str.length / 2));
   const upper = str.substr(Math.ceil(str.length / 2));

   return lower.split("").reverse().join("") === upper;
}

Or leave away all unneccessary conversions from your code:

function isPlaindrome(str) {
  const half = str.length / 2;
  for(var i = 0; i < half; i++)
    if(str[i] !== str[str.length - i - 1])
       return false;
  return true;
}

Two Ways to Check for Palindromes in JavaScript, How do you check if a word is a palindrome in JavaScript? palindrome(“A man, a plan, a canal. Panama”) should return true; palindrome(“never odd or even”) should return true; palindrome(“nope”) should return false; palindrome(“almostomla”) should return false; palindrome(“My age is 0, 0 si ega ym.”) should return true; palindrome(“1 eye for of 1 eye.”) should return false


Number prime test in JavaScript, or sentence that's spelled the same way both forward and backward, ignoring punctuation, case, and spacing. Note. Palindrome number. When a number doesn’t change it’ s value or meaning even after rotation from left to right or vice a versa, then the number is palindrome number. For example: 12321 after rotation 12321number is still same. JavaScript code to check palindrome number


Code :

There are multiple methods that you can use (dunno if they are optimal) :

Palindrom = _ => (_=''+_) === [..._].sort(_=>1).join``

Some more :

let isPalindrome = __ => (_=(__=__+'').length)==0||_==1?!0:__[0]==__.slice(-1)?isPalindrome(__.slice(1,-1)):!1

let isPalindrome = (s,i) => (i=i||0)<0||i>=(s=''+s).length>>1||s[i]==s[s.length-1-i]&&isPalindrome(s,++i);

let isPalindrome = (str) => {
  var len = ~~((str=str+'').length / 2);
  for (var i = 0; i < len; i++)
    if (str[i] !== str[str.length - i - 1])
      return false;
  return true;
}

How to write palindrome in JavaScript, How do you check if a number is prime in JavaScript? The entry is a palindrome. The entry is a palindrome. Entry is not a palindrome. Flowchart: Live Demo: See the Pen JavaScript -Check whether a passed string is palindrome or not-function-ex- 2 by w3resource (@w3resource) on CodePen. Improve this sample solution and post your code through Disqus. Previous: Write a JavaScript function that reverse a number.


11 ways to check for palindromes in JavaScript, function isPrime(num) { if (num === 2) { return true; } else if(num > 1){ for (var i = 2; i < num; i++) { if (num % i !== 0 ) { return true; } else if (num === i * i) { return false } else { return false; } } } else { return false; } } console. log(isPrime(121)); All these tools are available in bin folders so we set path upto bin folders. Classpath variable is set for providing a path for predefined Java classes which is used in our application. All classes are available in lib/rt.jar so we set classpath upto lib/rt.jar.


Three ways to check for palindromes in JavaScript, A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward or forward. The word “palindrome”  To check a number is palindrome or not without using any extra space Check if a number is Palindrome Given an integer, write a function that returns true if the given number is palindrome, else false. For example, 12321 is palindrome, but 1451 is not palindrome.


Javascript Algorithms #2: Palindromes - DEV Community ‍ ‍ , Here, we are going to learn how to check whether a given number is palindrome or not in JavaScript. 2 Optimal verification if a number is Palindrom in JS May 20 '18 2 spring-security wrong logged user Mar 7 '10 View all questions and answers →