I am trying to reverse a string in JavaScript using Reduce method. But I am getting an error. Can anyone suggest me how to solve an error?

code ::

var reverseString = function(s) {
   return s.split("").reduce((rev, char) => char + rev, '');
};

reverseString(['h', 'e', 'l', 'l', 'o']);

output ::

I am trying to reverse a string in JavaScript using Reduce method. But I am getting an error. Can anyone suggest me how to solve an error?

code ::

var reverseString = function(s) {
   return s.split("").reduce((rev, char) => char + rev, '');
};

reverseString(['h', 'e', 'l', 'l', 'o']);

output ::

• javascript
• arrays

• You're passing it an array. .split() is for strings not arrays. I think you wanted .join() – Aniket G Commented Mar 30, 2019 at 1:03
• Pass the string in as 'hello' not as an array. – Vappor Washmade Commented Mar 30, 2019 at 1:03
• 2 Please post actual code not images of code. Nobody can copy it to test or modify for answers. minimal reproducible example Also provide expected results – charlietfl Commented Mar 30, 2019 at 1:04
• 2 I don't think .reduce() is the right tool for the job. – Pointy Commented Mar 30, 2019 at 1:05
• Indeed, it appears there is already a function which will do this. – Heretic Monkey Commented Mar 30, 2019 at 1:12

3 Answers 3

You almost had it, just needed to remove the String.prototype.split() method, because String.split() doesn't work on arrays. Example:

var reverseString = function(s) {
  return s.reduce((rev, char) => char+rev, "").split("");
}
console.log(reverseString(['h', 'e', 'l', 'l', 'o']));

Check if you really want to reverse a string or an array. Try this if it's a string

var reverseString = function(s) {
	return s.split('').reverse().join('');
}

console.log(reverseString('hello'));

function reverseString(str) {
  return str.split('').reduce((rev, char) => char + rev, "");
}

or

function reverseString(str) {
  return str.split('').reverse().join('')
}