interface StringConstructor {
	IsNullOrEmpty: (value: string) => boolean;
	Format: (format: string, ...args: any[]) => string;
}

String.IsNullOrEmpty = function (value: string): boolean {
	return value === undefined || value === null || value.trim() === "";
};

String.Format = function (format: string, ...args: any[]): string {
	return format.replace(/{(\d+)}/g, (match, index) => {
		let value: any = args[index];
		if (value === null || value === undefined) { return ""; }
		return "" + value;
	});
};