# numerating chapters in book- format

I would like to have the following formatting in the table of contents:

1. Chapter 1
1.1 Section 1
1.2 Section 2


And also I want to use \chapter but instead of appearing.

Chapter 1

Chapter 1


I want

1. Chapter 1.


I have tried different combinations (using the titlesec package without success).

Thank you!

Here's one possibility. titlesec was used to change the format for chapter headings and tocloft to add the period after the unit number in the ToC:

\documentclass{book}
\usepackage{titlesec}
\usepackage{tocloft}

\titleformat{\chapter}
{\normalfont\huge\bfseries}{\thechapter.}{1em}{\Huge}
\renewcommand\cftchapaftersnum{.}

\begin{document}

\tableofcontents
\chapter{A test chapter}
\section{Test section one one}
\section{Test section one two}

\end{document}


An image of the resulting ToC:

An image of the new chapter heading format: