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function is not described

WP_User::set_role() WP 2.0.0

Set the role of the user.

This will remove the previous roles of the user and assign the user the new one. You can set the role to an empty string and it will remove all of the roles from the user.

This is a method of the class: WP_User

Hooks from the method
Return

Null. Nothing.

Usage

$WP_User = new WP_User();
$var = $WP_User->set_role( $role );
$role(string) (required)
Role name.

Changelog

Since 2.0.0 Introduced.

Code of WP User::set role: wp-includes/class-wp-user.php WP 5.4.2

<?php
public function set_role( $role ) {
	if ( 1 == count( $this->roles ) && current( $this->roles ) == $role ) {
		return;
	}

	foreach ( (array) $this->roles as $oldrole ) {
		unset( $this->caps[ $oldrole ] );
	}

	$old_roles = $this->roles;
	if ( ! empty( $role ) ) {
		$this->caps[ $role ] = true;
		$this->roles         = array( $role => true );
	} else {
		$this->roles = false;
	}
	update_user_meta( $this->ID, $this->cap_key, $this->caps );
	$this->get_role_caps();
	$this->update_user_level_from_caps();

	/**
	 * Fires after the user's role has changed.
	 *
	 * @since 2.9.0
	 * @since 3.6.0 Added $old_roles to include an array of the user's previous roles.
	 *
	 * @param int      $user_id   The user ID.
	 * @param string   $role      The new role.
	 * @param string[] $old_roles An array of the user's previous roles.
	 */
	do_action( 'set_user_role', $this->ID, $role, $old_roles );
}