WP_CLI

SynopsisParser::is_optional │ private static │ WP-CLI 1.0

An optional parameter is surrounded by square brackets.

Method of the class: SynopsisParser{}

No Hooks.

Returns

Array.

Usage

$result = SynopsisParser::is_optional( $token );
$token(string) (required)
.

SynopsisParser::is_optional() code WP-CLI 2.13.0-alpha

wp-cli/php/WP_CLI/SynopsisParser.php 
private static function is_optional( $token ) {
	if ( '[' === substr( $token, 0, 1 ) && ']' === substr( $token, -1 ) ) {
		return [ true, substr( $token, 1, -1 ) ];
	}

	return [ false, $token ];
}