form_dropdown()

function form_dropdown(string $name, array $options, string|int|null $selected_key = null, array $attributes = []): string

Description

Generates an HTML select menu (dropdown). Creates a list of options where users can select one or multiple values.

Parameters

Parameter	Type	Description
$name	string	The name attribute for the select element.
$options	array<string\|int,string>	Associative array where keys are option values and values are display text.
$selected_key	string\|int\|null	(optional) The key of the option that should be selected.
$attributes	array	(optional) HTML attributes for the select element. Defaults to an empty array ([]).

Return Value

Type	Description
string	The generated HTML select menu with options.

Example #1: Basic Dropdown

PHP

$options = [
    'small' => 'Small',
    'medium' => 'Medium', 
    'large' => 'Large'
];
echo form_dropdown('size', $options);

Example #2: Dropdown with Selected Value

PHP

$options = [
    'pending' => 'Pending',
    'in_progress' => 'In Progress',
    'completed' => 'Completed'
];
echo form_dropdown('status', $options, 'in_progress');

Example #3: Dropdown with Placeholder Option

PHP

$options = [
    '' => '-- Select Country --',
    'us' => 'United States',
    'ca' => 'Canada'
];
$attributes = ['required' => 'required'];
echo form_dropdown('country', $options, '', $attributes);

Example #4: Multiple Selection Dropdown

PHP

$options = [
    'php' => 'PHP',
    'js' => 'JavaScript', 
    'python' => 'Python'
];
$attributes = [
    'multiple' => 'multiple',
    'size' => '3'
];
echo form_dropdown('languages[]', $options, ['php', 'python'], $attributes);

Notes

For multiple select dropdowns, append [] to the field name and pass selected values as an array.
Option values and display text are automatically HTML-escaped for security.
Selection uses string comparison, so '1' matches 1.
Use post('field_name') for single selections and post('field_name[]') for multiple selections.
Empty string keys create placeholder options useful for required fields.