Merge pull request #9 from learnerjay/master

Check a string is palindrome or not

Author: gouravthakur39

JSAlgorithms/CheckPalindrone.js

@@ -0,0 +1,39 @@
+// Write a JavaScript function that checks whether a passed string is palindrome or not? 
+
+function check_Palindrome(str_entry){
+ // Change the string into lower case and remove all non-alphanumeric characters
+ var cstr = str_entry.toLowerCase().replace(/[^a-zA-Z0-9]+/g,'');
+ var ccount = 0;
+ // Check whether the string is empty or not
+ if(cstr==="") {
+ console.log("Nothing found!");
+ return false;
+ }
+ // Check if the length of the string is even or odd 
+ if ((cstr.length) % 2 === 0) {
+ ccount = (cstr.length) / 2;
+ } else {
+ // If the length of the string is 1 then it becomes a palindrome
+ if (cstr.length === 1) {
+ console.log("Entry is a palindrome.");
+ return true;
+ } else {
+ // If the length of the string is odd ignore middle character
+ ccount = (cstr.length - 1) / 2;
+ }
+ }
+ // Loop through to check the first character to the last character and then move next
+ for (var x = 0; x < ccount; x++) {
+ // Compare characters and drop them if they do not match 
+ if (cstr[x] != cstr.slice(-1-x)[0]) {
+ console.log("Entry is not a palindrome.");
+ return false;
+ }
+ }
+ console.log("The entry is a palindrome.");
+ return true;
+ }
+ check_Palindrome('madam');
+ check_Palindrome('nurses run');
+ check_Palindrome('fox');
+