Duplicate Character Counter in Php

Welcome to the Duplicate Character Counter 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 provide a string");
}

function duplicate_character_counter($str)
{
    // Count number of occurances of each character
    $counts = array();
    $len = strlen($str);
    for ($index = 0; $index < $len; $index++)
    {
        $ch = $str[$index];
        if (!array_key_exists($ch, $counts))
        {
            $counts[$ch] = 0;
        }

        $counts[$ch] += 1;
    }

    return $counts;
}

function show_duplicate_character_counts($counts)
{
    // Show characters that have duplicates and keep track if
    // duplicates found
    $has_dupes = FALSE;
    foreach ($counts as $char => $count)
    {
        if ($count > 1)
        {
            echo "${char}: ${count}\n";
            $has_dupes = TRUE;
        }
    }

    // Indicate if no duplicates found
    if (!$has_dupes)
    {
        echo "No duplicate characters\n";
    }
}

// Get 1st argument. Exit if too few arguments or empty argument
if (count($argv) < 2 || empty($argv[1]))
{
    usage();
}

// Count duplicate characters
$str = $argv[1];
$counts = duplicate_character_counter($str);

// Show all duplicate character counts in order in which they occurred in string (if any)
show_duplicate_character_counts($counts);

Duplicate Character Counter 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.