JavaScript: Alphanumeric characters that are palindromes
JavaScript String: Exercise-50 with Solution
A palindrome is a word, number, phrase, or other sequence of symbols that reads the same backwards as forwards, such as the words madam or racecar, the date/time stamps 11/11/11 11:11 and 02/02/2020, and the sentence: "A man, a plan, a canal – Panama". The 19-letter Finnish word saippuakivikauppias (a soapstone vendor), is the longest single-word palindrome in everyday use, while the 12-letter term tattarrattat (from James Joyce in Ulysses) is the longest in English.
Write a JavaScript program to check if a given string contains alphanumeric characters that are palindromes regardless of special characters and letter case.
Test Data:
('$22_|1372^2731|_22') -> true
('12%^&2') -> false
('234%$$%432') -> true
(1234) -> "It must be string"
('aba%$aba') -> true
('Aba%$aba') -> true
Sample Solution:
HTML Code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JavaScript function to check Alphanumeric characters that are palindromes</title>
</head>
<body>
</body>
</html>
JavaScript Code:
const test = (alpha_text) => {
if (typeof alpha_text !== 'string') {
return 'It must be string'
}
const new_text = alpha_text.replace(/[^a-z0-9]+/ig, '').toLowerCase()
const mid_index = new_text.length >> 1
for (let i = 0; i < mid_index; i++) {
if (new_text.at(i) !== new_text.at(~i))
{
return false
}
}
return true
}
console.log(test('$22_|1372^2731|_22'))
console.log(test('12%^&2'))
console.log(test('234%$$%432'))
console.log(test(1234))
console.log(test('aba%$aba'))
console.log(test('Aba%$aba'))
Sample Output:
true false true It must be string true true
Flowchart:

Live Demo:
See the Pen javascript-string-exercise-50 by w3resource (@w3resource) on CodePen.
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