The PHP array wrapper to get scalar.

ReadOnlyScalarMap.php

<?php
/**
 * Provides the methods to get scalar from single-dimensional-array.
 * This code is designed for the legacy version, such as PHP 5.2.
 *
 * @copyright 2021 koohq
 * @license https://creativecommons.org/publicdomain/zero/1.0/legalcode CC0
 */
class ReadOnlyScalarMap
{
    /** @var array source */
    private $source;

    /**
     * Initializes a new instance of ReadOnlyScalarMap using the specified array.
     *
     * @param array $source the source array.
     */
    public function __construct(array $source)
    {
        $this->source = $source;
    }

    /**
     * Gets the value associated with the specified key and converts to the boolean value.
     *
     * @param string|int $key The key of the value to get.
     * @return bool the boolean value associated with the specified key if the key is found; otherwise, false.
     */
    public function getBool($key)
    {
        // `boolval()` is undefined on PHP 5.2.
        $value = $this->getOrDefault($key);
        return !empty($value);
    }

    /**
     * Gets the value associated with the specified key and converts to the float value.
     *
     * @param string|int $key The key of the value to get.
     * @return float the float value associated with the specified key if the key is found; otherwise, 0.
     */
    public function getFloat($key)
    {
        return floatval($this->getOrDefault($key));
    }

    /**
     * Gets the value associated with the specified key and converts to the integer value.
     *
     * @param string|int The key of the value to get.
     * @return int the integer value associated with the specified key if the key is found; otherwise, 0.
     */
    public function getInt($key)
    {
        return intval($this->getOrDefault($key));
    }

    /**
     * Gets the value associated with the specified key and converts to the string value.
     *
     * @param string|int $key The key of the value to get.
     * @return string the boolean value associated with the specified key if the key is found; otherwise, empty string.
     */
    public function getString($key)
    {
        return strval($this->getOrDefault($key));
    }

    /**
     * Gets the value associated with the specified key.
     *
     * @param string|int $key The key of the value to get.
     * @return mixed the value associated with the specified key if the key is found; otherwise, null.
     */
    private function getOrDefault($key)
    {
        return isset($this->source[$key]) ? $this->source[$key] : null;
    }
}