chapter title long and necessity to cut it

Question

my chapter title is too long and I have the necessity to cut it in two different lines. well which could be the best way to cut it?I tried using \newline but unfortunately this modification affects also title page in every page.

Answer 1

Sectioning commands like \chapter feature an optional argument that will be used in the header/footer and the table of contents. So use the optional argument of \chapter and omit the line break there.

\documentclass{book}

\usepackage{lipsum}

\begin{document}

\chapter[A very long chapter title]{A very long \\chapter title}

\lipsum

\end{document}