<?php

final class ArrayTools
{
    public static function get_property(array $fields, string $field, string $type)
    {
        if (array_key_exists($field, $fields) === false)
        {
            throw new Exception('field');
        }
        
        $value = $fields[$field];
        
        if (gettype($value) !== $type)
        {
            throw new Exception(gettype($value) . ' === ' . $type);
        }
        
        return $value;
    }
}

(new class
{
    public function check_fields(array $fields): void
    {
        echo ArrayTools::get_property($fields, 'lens', 'integer');
        echo ArrayTools::get_property($fields, 'name', 'string');
        
        # === property exception ===
        # echo ArrayTools::get_property($fields, 'null', 'NULL');
        
        # === datatype exception ===
        # echo ArrayTools::get_property($fields, 'time', 'NULL');
    }
    
    public function __construct()
    {
        $this->check_fields(['name' => 'anna', 'lens' => 17, 'time' => 100]);
    }
});