\documentclass[10pt,a4paper]{article} % Packages \usepackage{fancyhdr} % For header and footer \usepackage{multicol} % Allows multicols in tables \usepackage{tabularx} % Intelligent column widths \usepackage{tabulary} % Used in header and footer \usepackage{hhline} % Border under tables \usepackage{graphicx} % For images \usepackage{xcolor} % For hex colours %\usepackage[utf8x]{inputenc} % For unicode character support \usepackage[T1]{fontenc} % Without this we get weird character replacements \usepackage{colortbl} % For coloured tables \usepackage{setspace} % For line height \usepackage{lastpage} % Needed for total page number \usepackage{seqsplit} % Splits long words. %\usepackage{opensans} % Can't make this work so far. Shame. Would be lovely. \usepackage[normalem]{ulem} % For underlining links % Most of the following are not required for the majority % of cheat sheets but are needed for some symbol support. \usepackage{amsmath} % Symbols \usepackage{MnSymbol} % Symbols \usepackage{wasysym} % Symbols %\usepackage[english,german,french,spanish,italian]{babel} % Languages % Document Info \author{blakecromar} \pdfinfo{ /Title (c-qstring.pdf) /Creator (Cheatography) /Author (blakecromar) /Subject (C++ (QString) Cheat Sheet) } % Lengths and widths \addtolength{\textwidth}{6cm} \addtolength{\textheight}{-1cm} \addtolength{\hoffset}{-3cm} \addtolength{\voffset}{-2cm} \setlength{\tabcolsep}{0.2cm} % Space between columns \setlength{\headsep}{-12pt} % Reduce space between header and content \setlength{\headheight}{85pt} % If less, LaTeX automatically increases it \renewcommand{\footrulewidth}{0pt} % Remove footer line \renewcommand{\headrulewidth}{0pt} % Remove header line \renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit % This two commands together give roughly % the right line height in the tables \renewcommand{\arraystretch}{1.3} \onehalfspacing % Commands \newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour \newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols \newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns \newcommand{\tn}{\tabularnewline} % Required as custom column type in use % Font and Colours \definecolor{HeadBackground}{HTML}{333333} \definecolor{FootBackground}{HTML}{666666} \definecolor{TextColor}{HTML}{333333} \definecolor{DarkBackground}{HTML}{A33E8B} \definecolor{LightBackground}{HTML}{F9F2F7} \renewcommand{\familydefault}{\sfdefault} \color{TextColor} % Header and Footer \pagestyle{fancy} \fancyhead{} % Set header to blank \fancyfoot{} % Set footer to blank \fancyhead[L]{ \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{C} \SetRowColor{DarkBackground} \vspace{-7pt} {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}} } \end{tabulary} \columnbreak \begin{tabulary}{11cm}{L} \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{C++ (QString) Cheat Sheet}}}} \\ \normalsize{by \textcolor{DarkBackground}{blakecromar} via \textcolor{DarkBackground}{\uline{cheatography.com/218070/cs/48198/}}} \end{tabulary} \end{multicols}} \fancyfoot[L]{ \footnotesize \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{LL} \SetRowColor{FootBackground} \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}} \\ \vspace{-2pt}blakecromar \\ \uline{cheatography.com/blakecromar} \\ \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}} \\ \vspace{-2pt}Not Yet Published.\\ Updated 18th June, 2026.\\ Page {\thepage} of \pageref{LastPage}. \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}} \\ \SetRowColor{white} \vspace{-5pt} %\includegraphics[width=48px,height=48px]{dave.jpeg} Measure your website readability!\\ www.readability-score.com \end{tabulary} \end{multicols}} \begin{document} \raggedright \raggedcolumns % Set font size to small. Switch to any value % from this page to resize cheat sheet text: % www.emerson.emory.edu/services/latex/latex_169.html \footnotesize % Small font. \begin{tabularx}{17.67cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Qstring}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{// Qt's Unicode string class, used wherever you would use std::string in a Qt codebase. It handles \newline // international characters and encodings natively, and provides methods for common string operations // like splitting, trimming, and replacing. It interoperates with std::string via fromStdString() and \newline // toStdString(). \newline \newline QString qString = \seqsplit{QString::fromStdString(stdString);} \newline QString combined = \seqsplit{QStringLiteral("literalPrefix")} + qString;} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{17.67cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{QString::fromStdString}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{// A static factory method on QString that converts a std::string into a QString, bridging the standard \newline // C++ and Qt string ecosystems. It internally constructs a new QString by copying the character data \newline // across from the std::string. It is called on the class itself rather than an instance, signalling that it is a \newline // QString concern. \newline \newline QString qString = \seqsplit{QString::fromStdString(stdString);}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{17.67cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{QStringLiteral}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{QString literal = \seqsplit{QStringLiteral("hardcodedValue");}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{A Qt macro that creates a QString from a hardcoded string literal at compile time rather than runtime, avoiding any memory allocation. It is used wherever you have a fixed string value baked directly into the code rather than a variable. For dynamic values coming from variables, QString::fromStdString() is used instead.} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{17.67cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{QString::fromLocal8Bit}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{QString errorOutput = \seqsplit{QString::fromLocal8Bit(rawBytes);}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{A static factory method on QString that converts raw byte data into a QString using the local system's text encoding. It is used specifically for reading process error output since readAllStandardError() returns raw bytes rather than a proper string. It is preferred over fromStdString() sometimes because error messages from system processes are encoded in the local system encoding rather than UTF-8.} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{17.67cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{QString::trimmed()}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{QString cleaned = qString.trimmed();} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \SetRowColor{LightBackground} \mymulticolumn{1}{x{17.67cm}}{A method on QString that returns a copy of the string with all leading and trailing whitespace removed, including spaces, newlines, and tabs. It is commonly used when reading output from external processes since they often append a newline to the end of their output. It does not modify the original string but returns a new cleaned copy.} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \end{document}