wp_unique_id() │ WP 5.0.3

Gets unique ID.

This is a PHP implementation of Underscore's uniqueId method. A static variable contains an integer that is incremented with each call. This number is returned with the optional prefix. As such the returned value is not universally unique, but it is unique across the life of the PHP process.

No Hooks.

Return

String. Unique ID.

Usage

wp_unique_id( $prefix );
$prefix(string)
Prefix for the returned ID.
Default: ''

Examples

0

#1 Example of function operation 

echo wp_unique_id();            //> 5 (most likely the function has already been called in the engine, so you are unlikely to get 1)
echo wp_unique_id();            //> 6
echo wp_unique_id( 'field_' );  //> field_7
echo wp_unique_id();            //> 8
echo wp_unique_id();            //> 9
echo wp_unique_id( 'name_' );   //> name_10
echo wp_unique_id();            //> 11
echo wp_unique_id();            //> 12
0

#2 Creating unique IDs for the label + input tag association 

// Generate unique identifiers
$unique_id = wp_unique_id( 'field_' );

// Output HTML
echo sprintf( '<label for="%s">Enter text:</label>', $unique_id );
echo sprintf( '<input id="%s" type="text" name="text_input">', $unique_id );

Changelog

Since 5.0.3 Introduced.

wp_unique_id() code WP 6.7.1

wp-includes/functions.php 
function wp_unique_id( $prefix = '' ) {
	static $id_counter = 0;
	return $prefix . (string) ++$id_counter;
}

Helper Functions