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PHP function Exercises: Checks whether a passed string is a palindrome or not

PHP function: Exercise-6 with Solution

Write a PHP function that checks whether a passed string is a palindrome or not?

A palindrome is word, phrase, or sequence that reads the same backward as forward, e.g., madam or nurses run.

Pictorial Presentation:

PHP function Exercises: Checks whether a passed string is a palindrome or not

Sample Solution:

PHP Code:

<?php
function check_palindrome($string) 
{
  if ($string == strrev($string))
      return 1;
  else
	  return 0;
}
echo check_palindrome('madam')."\n";
?>

Sample Output:

1

Flowchart :

Flowchart: Checks whether a passed string is a palindrome or not

PHP Code Editor:

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PHP: Tips of the Day

Get first key in a (possibly) associative array?

Starting from PHP 7.3, there is a new built in function called array_key_first() which will retrieve the first key from the given array without resetting the internal pointer. Check out the documentation for more info.

You can use reset and key:

reset($array);
$first_key = key($array);

It's essentially the same as your initial code, but with a little less overhead, and it's more obvious what is happening.

Just remember to call reset, or you may get any of the keys in the array. You can also use end instead of reset to get the last key.

If you wanted the key to get the first value, reset actually returns it:

$first_value = reset($array);

There is one special case to watch out for though (so check the length of the array first):

$arr1 = array(false);
$arr2 = array();
var_dump(reset($arr1) === reset($arr2)); // bool(true)

Ref : https://bit.ly/32ecxHN