Oh my gods! This is what passes for an answer to "identify a palindrome"? All of
that?? 59 lines to ensure a string is equal to itself reversed (hint-hint, nudge-nudge)? Why?
'use strict'; // avoid ambiguity and sloppy errors
/**
* Tests whether or not a given string is a Palindrome
* @param {string} stringToTest - the string to test.
*/
function isPalindrome(stringToTest) {
var start = 0,
end;
// make sure we have a string.
if (typeof stringToTest !== "string") {
// throw if we didn't get a string
throw new TypeError("isPalindrome() expected a string, but got " +
Object.prototype.toString.call(stringToTest) + " instead!");
}
// normalize string by lowercasing and removing non-word characters
stringToTest = stringToTest
.toLowerCase()
.replace(/[^a-z0–9]/ig, '');
if (stringToTest.length === 0) {
// warn if we have no valid characters to test
console.log("No valid characters to test, treated as empty string" +
"\nStack: \n" + new Error().stack);
return true; // an empty string is a palindrome.
}
end = stringToTest.length - 1;
// Compare characters from outside in. Stop when we get to the middle.
while (start
}
// tests (should be in a separate file using a test framework)
console.log(isPalindrome("something that is not a palindrome") + " = false");
console.log(isPalindrome("something that is \n not a palindrome") + " = false");
console.log(isPalindrome("race \n car") + " = true");
console.log(isPalindrome("") + " = true + warn");
console.log(isPalindrome(" ") + " = true + warn");
console.log(isPalindrome("1221") + " = true");
console.log(isPalindrome("0") + " = true");
console.log(isPalindrome("racecar") + " = true");
console.log(isPalindrome("No 'x' in Nixon!") + " = true");
console.log(isPalindrome("~~!~!~") + " = true + warn");
console.log(isPalindrome("Momsie") + " = false");
console.log(isPalindrome(12)); // blow up
console.log(isPalindrome(undefined)); // blow up
console.log(isPalindrome(null)); // blow up
Godsdammit- I'm pretty sure I'm not missing the point here. That is a ridiculous amount of overengineering, it should not be accepted as an answer to such a simple question, under any circumstances.