Javascript Interview Question: Palindrome

palindrome.js

/* 
Create a function that checks if a string is a palindrome.
*/

//Most direct solution
function palindrome(str) {
	return str === str.split('').reverse().join('');
}

//Solution that uses Array.every() helper. Note, this is inefficient as you do twice the work.
function palindrome(str) {
	return str.split('').every((char, i) => char === str[str.length - i - 1]);
}

//Jest
test('It should return true when the input is a palindrome.', () => {
	expect(palindrome('aba')).toBeTruthy();
});

test('It should return false when the input is not a palindrome.', () => {
	expect(palindrome('abc')).toBeFalsy();
});

//Try it
console.log(palindrome('aba'));