Palindromic Number in Php

Welcome to the Palindromic Number in Php page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

<?php
function usage()
{
    exit("Usage: please input a non-negative integer");
}

function parse_int($str_value)
{
    // Remove leading and trailing spaces
    $str_value = trim($str_value);

    // Make sure all digits
    if (preg_match("/[+-]?^\d+$/", $str_value) === FALSE)
    {
        return FALSE;
    }

    // Make sure valid integer
    if (
        filter_var(
            $str_value,
            FILTER_VALIDATE_INT,
            array(
                'options' => array(
                    'decimal' => TRUE,
                    'min_range' => PHP_INT_MIN,
                    'max_range' => PHP_INT_MAX
                )
            )
        ) === FALSE
    )
    {
        return FALSE;
    }

    return intval($str_value);
}

function is_palindromic_number($value)
{
    // Convert number to string
    $str = "${value}";

    // Check if palindrome
    $len = strlen($str);
    $is_palindrome = TRUE;
    for ($left = 0, $right = $len - 1; $left < $right && $is_palindrome; $left++, $right--)
    {
        $is_palindrome = ($str[$left] == $str[$right]);
    }

    return $is_palindrome;

}

// Exit if too few arguments
if (count($argv) < 2)
{
    usage();
}

// Parse 1st command-line argument and exit if invalid or negative
$value = parse_int($argv[1]);
if ($value === FALSE || $value < 0)
{
    usage();
}

// Check if number is a palindrome and display results
$is_palindrome = is_palindromic_number($value);
printf("%s\n", $is_palindrome ? "true" : "false");

Palindromic Number in Php was written by:

• rzuckerm

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.