How to write "Chapter 1" instead of "1" in table of contents of a thesis

Question

Suggest me LaTeX command and package on how the words Chapter 1 can be appeared in the table of contents instead of just 1 and so on for the next chapters. Following is the template of the thesis of our university:

\documentclass[12pt,openany,oneside]{book}
\usepackage[pdftex]{graphicx}
\usepackage[a4paper,portrait,left=1.5in,
right=1in,top=1in, bottom=1.33in, footskip=0.33in]{geometry}
%\usepackage{sectsty}
%\sectionfont{\fontsize{12}{15}\selectfont}
\usepackage{titlesec}
\usepackage{lipsum}
%\titleformat{\chapter}[display]
%{\normalfont\Large\filcenter\sffamily}
%{\vspace*{\fill}
    %\titlerule[1pt]
    %\vspace{1pc}
    %\LARGE\MakeUppercase{\chaptertitlename}~\thechapter}
%{1pc}
%{\titlerule\Huge}
%[\vspace*{\fill}\newpage]

\titleformat{\chapter}[display]
{\normalfont\huge\bfseries\centering}{\chaptertitlename
    \ \thechapter}{20pt}{\Huge}
\titlespacing*{\chapter}{0pt}{250pt}{40pt}
\usepackage{epstopdf}
\usepackage{subfigure}
\usepackage{epsfig}
\usepackage{color}
%\usepackage{a4wide}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{enumitem}
\usepackage{lmodern}
\usepackage[T1]{fontenc}
\usepackage{ntheorem}
\usepackage[normalem]{ulem}
\usepackage{chngcntr}
%\usepackage[pdfencoding = auto, psdextra, bookmarksdepth = 4]{hyperref}




%\usepackage{microtype}
\overfullrule=5pt
\hfuzz=20pt
\vfuzz=20pt
\hbadness=10000
\vbadness=\maxdimen
\renewcommand{\chaptermark}[1]{
    \markboth{\chaptername\  \thechapter.\ #1}{}}
\renewcommand{\sectionmark}[1]{
    \markright {\thesection.\ #1}}
\parindent0pt
\newlength{\defbaselineskip}
\setlength{\defbaselineskip}{\baselineskip}
\newcommand{\setlinespacing}[1]%
{\setlength{\baselineskip}{#1 \defbaselineskip}}
\newcommand{\doublespacing}{\setlength{\baselineskip}%
    {2.0 \defbaselineskip}}
\newcommand{\singlespacing}{\setlength{\baselineskip}{\defbaselineskip}}
\setlinespacing{1.5}
\newtheorem*{theorem-non}{Theorem}
\newtheorem{definition}{Definition}[chapter]
\newtheorem{lemma}{Lemma}[chapter]
\newtheorem{theorem}{Theorem}[chapter]
\newtheorem{remark}{Remark}[chapter]
\newtheorem{example}{Example}[chapter]
\newtheorem{corollary}{Corollary}[chapter]
\newenvironment{proof}%
{\medskip\par\noindent{\bf Proof\;}}%
{\hspace{\fill}$\Box$\medskip\par}
\numberwithin{equation}{chapter}
\numberwithin{theorem}{chapter}
\numberwithin{lemma}{chapter}
\numberwithin{corollary}{chapter}
\numberwithin{example}{chapter}
\numberwithin{remark}{chapter}
\numberwithin{definition}{chapter}
\renewcommand{\bibname}{}
\hyphenpenalty 50
\newtheorem{property}{Property}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\newcommand{\cchapter}[1]{\chapter[#1]}{\centering #1}}
%%%%%%%%%%%%%%%%%%%%%
%\newgeometry{left=1.5in, right=1.0in, bottom=1.75in, top=1in, footskip=0.75in}
%\addtolength{\oddsidemargin}{0.5cm}
%    \addtolength{\evensidemargin}{0.5cm}
%    \addtolength{\textwidth}{0.0cm}
%    \addtolength{\topmargin}{0.0cm}
%    \addtolength{\textheight}{0.0cm}
%%%%%%%%%%%%%%%%%%%
\usepackage[noabbrev]{cleveref}
\begin{document}
\pagestyle{plain} \setlinespacing{1.5}
%\input{Acknowledgement}
\newpage
\input{mytitle.tex}
%%%%%%%%%%%%%%%%%%%%
\newpage
\pagenumbering{arabic}
\setcounter{page}{1}
\input{chap1.tex}
%%%%%%%%%%%%%%%%%%
\input{chap2.tex}
%%%%%%%%%%%%%%%%%%
\input{chap3.tex}
%%%%%%%%%%%%%%%%
\input{chap4.tex}
%%%%%%%%%%%%%%%%%
\input{chap5.tex}
%%%%%%%%%%%%%%%%%%%
\input{chap6.tex}
%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%
\input{chap7.tex}
%%%%%%%%%%%%%%%%%%%
\input{chap8.tex}
\input{bib.tex}
%%%%%%%%%%%%%%%
\end{document}

Table of contents have the following command:

\newpage
\tableofcontents

Answer 1

I suggest you employ the tocloft package to achieve your formatting objective. Observe that the only thing the code shown below does is to insert the word "Chapter" (and space) before the chapter number. In particular, the appearance of section-level entries in the Table of Contents is not modified.

\documentclass{book}

\usepackage{calc} % for '\widthof' macro
\usepackage[titles]{tocloft}
\renewcommand\cftchappresnum{Chapter }
\cftsetindents{chap}{0pt}{\widthof{\large\textbf{Chapter 1}}}

\begin{document}
\tableofcontents

\chapter{AAA}
\section{A1}
\section{A2}

\chapter{BBB}
\section{B1}
\section{B2}

\end{document}