# The lists environment

## Lists are actually very simple to create.

List is really easy to create

\begin{itemize}
\item One entry in the list
\item Another entry in the list
\end{itemize}

List is really easy to create
• One entry in the list
• Another entry in the list
To create a (unordered) list you have to declare the itemize environment and then put the entries inside.

## Unordered lists

The unordered (unnumbered) lists are produced by the itemize environment. Each entry must be preceded by the control sequence \item.
\begin{itemize}
\item The individual entries are indicated with a black dot, a so-called bullet.
\item The text in the entries may be of any length.
\end{itemize}

• The individual entries are indicated with a black dot, a so-called bullet.
• The text in the entries may be of any length.

## Ordered lists

Ordered list have the same syntax inside a different environment:
\begin{enumerate}
\item The labels consists of sequential numbers.
\item The numbers starts at 1 with every call to the enumerate environment.
\end{enumerate}

1. The labels consist of sequential numbers.
2. The numbers start at 1 with every call to the enumerate environment.
The ordered lists are generated by a \enumerate environment and each entry must be preceded by the control sequence \item, which will automatically generate the number labelling the item. The enumerate labels consist of sequential numbers, these numbers start at 1 with every call to the enumerate environment.

## Nested Lists

In LATEX you can insert a list inside another list. The above lists may be included within one another, either mixed or of one type, to a depth of four levels.
\begin{enumerate}
\item The labels consist of sequential numbers.
\begin{itemize}
\item The individual entries are indicated with a black dot, a so-called bullet.
\item The text in the entries may be of any length.
\end{itemize}
\item The numbers start at 1 with every call to the enumerate environment.
\end{enumerate}

1. The labels consist of sequential numbers.
• The individual entries are indicated with a black dot, a so-called bullet.
• The text in the entries may be of any length.
2. The numbers start at 1 with every call to the enumerate environment.

## List styles

As many other LATEX elements, unordered and ordered list styles can be personalized.

### Ordered lists

The numbering styles change depending on the depth of the nested lists:
\begin{enumerate}
\item First level item
\item First level item
\begin{enumerate}
\item Second level item
\item Second level item
\begin{enumerate}
\item Third level item
\item Third level item
\begin{enumerate}
\item Fourth level item
\item Fourth level item
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}

1. First level item
2. First level item
1. Second level item
2. Second level item
1. Third level item
2. Third level item
1. Fourth level item
2. Fourth level item
The default numbering scheme is:
• Arabic number (1, 2, 3, ...) for Level 1
• Lowercase letter (a, b, c, ...) for Level 2
• Lowercase Roman numeral (i, ii, iii, ...) for Level 3
• Uppercase letter (A, B, C, ...) for Level 4.
These numbers can be changed by redefining the commands that typeset the numbers of various list levels. For example:
\renewcommand{\labelenumii}{\Roman{enumii}}
\begin{enumerate}
\item First level item
\item First level item
\begin{enumerate}
\item Second level item
\item Second level item
\begin{enumerate}
\item Third level item
\item Third level item
\begin{enumerate}
\item Fourth level item
\item Fourth level item
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}

1. First level item
2. First level item
1. Second level item
2. Second level item
1. Third level item
2. Third level item
1. Fourth level item
2. Fourth level item
The command \renewcommand{\labelenumii}{\Roman{enumii}} changes the second level to upper case Roman numeral. It is possible to change the labels of any level, replace labelenumii for one of the listed below.
• \labelenumi for Level 1
• \labelenumii for Level 2
• \labelenumiii for Level 3
• \labelenumiv for Level 4
The command must be placed in the preamble to change the labels globally or right before \begin{enumerate}
In numbered lists the counter is incremented by \item before it is printed, and starts from 1,a,i,A,I. This can be changed:
\renewcommand{\labelenumii}{\Roman{enumii}}
\begin{enumerate}
\item First level item
\item First level item
\begin{enumerate}
\setcounter{enumii}{4}
\item Second level item
\item Second level item
\begin{enumerate}
\item Third level item
\item Third level item
\begin{enumerate}
\item Fourth level item
\item Fourth level item
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}

1. First level item
2. First level item
1. Second level item
2. Second level item
1. Third level item
2. Third level item
1. Fourth level item
2. Fourth level item
To change the start number or letter you must use the \setcounter command. In the example, to change the start number of level 2 to V the command \setcounter{enumii}{4} was used.
To set the start number to any other counter change enumii for any of these:
• enumi for Level 1
• enumii for Level 2
• enumiii for Level 3
• enumiv for Level 4

### Unordered lists

The label scheme of unordered lists also changes depending on the depth of the nested list:
 \begin{itemize}
\item  First Level
\begin{itemize}
\item  Second Level
\begin{itemize}
\item  Third Level
\begin{itemize}
\item  Fourth Level
\end{itemize}
\end{itemize}
\end{itemize}
\end{itemize}

• First Level
• Second Level
• Third Level
• ·Fourth Level
The default label scheme for itemized lists is:
• Level 1 is \textbullet (•),
• Level 2 is \textendash (–) ,
• Level 3 is \textasteriskcentered (*)
• Level 4 is \textperiodcentered (·).
These labels can be changed by redefining the commands that typeset them for various list levels. For example, to change Level 1 to black square and Level 2 to white square we’ll use :
\renewcommand{\labelitemi}{$\blacksquare$}
\renewcommand\labelitemii{$\square$}
\begin{itemize}
\item  First Level
\begin{itemize}
\item  Second Level
\begin{itemize}
\item  Third Level
\begin{itemize}
\item  Fourth Level
\end{itemize}
\end{itemize}
\end{itemize}
\end{itemize}

• First Level
• Second Level
• Third Level
• ·Fourth Level
To redefine the label, use one of the next commands, depending on the level of list mark you intend to change:
• labelitemi for Level 1
• labelitemii for Level 2
• labelitemiii for Level 3
• labelitemiv for Level 4
You can also change the item label for a specific entry, for example:
\begin{itemize}
\item  Default item label for entry one
\item  Default item label for entry two
\item[$\square$]  Custom item label for entry three
\end{itemize}

• Default item label for entry one
• Default item label for entry two
• Custom item label for entry three
All you have to do is pass the desired mark as a parameter inside brackets to the item line.

### Available styles for numbered lists:

 Code Description \alph Lowercase letter (a, b, c, ...) \Alph Uppercase letter (A, B, C, ...) \arabic Arabic number (1, 2, 3, ...) \roman Lowercase Roman numeral (i, ii, iii, ...) \Roman Uppercase Roman numeral (I, II, III, ...)