uialert

Display alert dialog box

Syntax

uialert(fig,message,title)

uialert(___,Name,Value)

Description

uialert(fig,message,title) displays a modal dialog box in front of the specified figure window. The figure must be created with the uifigure function. The dialog box displays the specified message and has a title bar with the specified title. By default, the dialog box also contains an error icon and an OK button.

uialert(___,Name,Value) displays a dialog box with properties specified by one or more Name,Value arguments.

Examples

Alert App User to Error

Create a modal alert dialog box. The figure behind it is inaccessible until you close the dialog box.

fig = uifigure;
uialert(fig,"File not found.","Invalid File");

Create Multiline Modal Alert Dialog Box with Warning Icon

fig = uifigure;
message = ["Fire hazard!","Consider reducing temperature."];
uialert(fig,message,"Warning", ...
    "Icon","warning");

Display Formatted MATLAB Error

Create a figure and two matrices of different sizes.

fig = uifigure; 
A = rand(3);
B = ones(5);

Attempt to vertically concatenate the matrices. Handle any errors that occur by getting the error text and creating an alert dialog box in the figure, and then specify the error text as the dialog message. MATLAB^® error text often includes HTML formatting, so specify the dialog interpreter as 'html'. The error is displayed with a link to the documentation for the vertcat function.

try 
    C = vertcat(A,B);
catch ME 
    report = getReport(ME);
    uialert(fig,report,"Error Message","Interpreter","html");
end

Input Arguments

fig — Target figure

Figure object

Target figure, specified as a Figure object. The figure must be created with the uifigure function.

message — Message

character vector | cell array of character vectors | string array

Message, specified as a character vector, cell array of character vectors, or string array. The message can be any length.

To display multiple lines of text, use a cell array of character vectors or a string array, where each element in the array is a different line of text.

Example: 'Invalid value'

title — Title

character vector | string scalar

Title, specified as a character vector or string scalar. Long titles truncate and are followed by ellipses. The exact length at which a title is truncated depends on your system setup.

Spaces replace format characters, such as the newline (\n) character.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'Icon','warning'

CloseFcn — Alert dialog box close request function callback

'' (default) | function handle | cell array | character vector

The alert dialog box close request callback function, specified as one of these values:

• Function handle.

• Cell array in which the first element is a function handle. Subsequent elements in the cell array are the arguments to pass to the callback function.

• Character vector that is a valid MATLAB expression. MATLAB evaluates this expression in the base workspace.

The CloseFcn callback executes when the app user dismisses the alert dialog box by clicking the close button in the title bar or clicking the OK button. The CloseFcn function also executes when the app user closes the figure window for which the alert dialog box displays from the MATLAB command line. You can close a figure window from the command line using the close function.

Icon — Icon

'error' (default) | predefined icon | custom icon

Icon, specified as a predefined icon or a custom icon.

Predefined Icon

This table lists the values for the predefined icons. For example, to show the check mark icon, specify the name-value pair 'Icon','success'.

Value	Icon
'error' (default)
'warning'
'info'
'question'
'success'
''	No icon displays.

Custom Icon

Specify a custom icon as one of these values:

• A character vector that specifies the file name of an SVG, JPEG, GIF, or PNG image that is on the MATLAB path. Alternatively, you can specify a full path to the image file.

• A truecolor image array. See Working with Image Types in MATLAB for more information.

Modal — Modal

true (default) | false

Modal, specified as true or false.

A modal dialog box is one that makes the figure inaccessible until the dialog box is closed. However, it does not prevent additional dialog boxes from appearing.

Interpreter — Dialog text interpreter

'none' (default) | 'tex' | 'latex' | 'html'

Dialog text interpreter, specified as:

• 'none' — Display literal characters.

• 'tex'— Interpret text using a subset of TeX markup.

• 'latex'— Interpret text using a subset of LaTeX markup.

• 'html'— Interpret text using a subset of HTML markup.

TeX Markup

Use TeX markup to add superscripts and subscripts and to include special characters in the text.

Modifiers remain in effect until the end of the text. Superscripts and subscripts are an exception because they modify only the next character or the characters within the curly braces. When you set the interpreter to 'tex', the supported modifiers are as follows.

Modifier	Description	Example
^{ }	Superscript	'text^{superscript}'
_{ }	Subscript	'text_{subscript}'
\bf	Bold font	'\bf text'
\it	Italic font	'\it text'
\sl	Oblique font (usually the same as italic font)	'\sl text'
\rm	Normal font	'\rm text'
\fontname{specifier}	Font name — Replace specifier with the name of a font family. You can use this in combination with other modifiers.	'\fontname{Courier} text'
\fontsize{specifier}	Font size —Replace specifier with a numeric scalar value in point units.	'\fontsize{15} text'
\color{specifier}	Font color — Replace specifier with one of these colors: red, green, yellow, magenta, blue, black, white, gray, darkGreen, orange, or lightBlue.	'\color{magenta} text'
\color[rgb]{specifier}	Custom font color — Replace specifier with a three-element RGB triplet.	'\color[rgb]{0,0.5,0.5} text'

This table lists the supported special characters for the 'tex' interpreter.

Character Sequence	Symbol	Character Sequence	Symbol	Character Sequence	Symbol
\alpha	α	\upsilon	υ	\sim	~
\angle	∠	\phi	ϕ	\leq	≤
\ast	*	\chi	χ	\infty	∞
\beta	β	\psi	ψ	\clubsuit	♣
\gamma	γ	\omega	ω	\diamondsuit	♦
\delta	δ	\Gamma	Γ	\heartsuit	♥
\epsilon	ϵ	\Delta	Δ	\spadesuit	♠
\zeta	ζ	\Theta	Θ	\leftrightarrow	↔
\eta	η	\Lambda	Λ	\leftarrow	←
\theta	θ	\Xi	Ξ	\Leftarrow	⇐
\vartheta	ϑ	\Pi	Π	\uparrow	↑
\iota	ι	\Sigma	Σ	\rightarrow	→
\kappa	κ	\Upsilon	ϒ	\Rightarrow	⇒
\lambda	λ	\Phi	Φ	\downarrow	↓
\mu	µ	\Psi	Ψ	\circ	º
\nu	ν	\Omega	Ω	\pm	±
\xi	ξ	\forall	∀	\geq	≥
\pi	π	\exists	∃	\propto	∝
\rho	ρ	\ni	∍	\partial	∂
\sigma	σ	\cong	≅	\bullet	•
\varsigma	ς	\approx	≈	\div	÷
\tau	τ	\Re	ℜ	\neq	≠
\equiv	≡	\oplus	⊕	\aleph	ℵ
\Im	ℑ	\cup	∪	\wp	℘
\otimes	⊗	\subseteq	⊆	\oslash	∅
\cap	∩	\in	∈	\supseteq	⊇
\supset	⊃	\lceil	⌈	\subset	⊂
\int	∫	\cdot	·	\o	ο
\rfloor	⌋	\neg	¬	\nabla	∇
\lfloor	⌊	\times	x	\ldots	...
\perp	⊥	\surd	√	\prime	´
\wedge	∧	\varpi	ϖ	\0	∅
\rceil	⌉	\rangle	〉	\mid	|
\vee	∨	\langle	〈	\copyright	©

LaTeX Markup

Use LaTeX markup to format and display mathematical expressions, equations, and special characters. Use dollar symbols around the marked up text. For example, use '$\int_1^{20} x^2 dx$' for inline mode or '$$\int_1^{20} x^2 dx$$' for display mode.

The displayed text uses the default LaTeX font style. You can use LaTeX markup to change the font style.

MATLAB supports most standard LaTeX math mode commands. For more information, see Supported LaTeX Commands.

HTML Markup

Use HTML markup to display links and customize font styles.

The interpreter supports a subset of HTML markup. As a general guideline, the interpreter supports text-related tags and styles. Unsupported tags and styles are ignored.

This table lists the supported elements and element attributes.

HTML Element	Attributes	Description
a	style, target, href, title	Hyperlink
abbr	style, title	Abbreviation or acronym
address	style	Contact information
article	style	Self-contained, independent content
aside	style	Content indirectly related to the main content
b	style	Bold text
bdi	style, dir	Content formatted in a different direction from surrounding text
bdo	style, dir	Content formatted in a different direction from surrounding text
big	style	Text one font size level larger than surrounding text (obsolete in HTML5)
blockquote	style, cite	Extended quotation
br	n/a	Line break
caption	style	Caption or title of a table
center	style	Content centered horizontally
cite	style	Title of a creative work
code	style	Fragment of code
col	style, align, valign, span, width	Column within a table
colgroup	style, align, valign, span, width	Group of columns within a table
dd	style	Term or value in a description list
del	style, datetime	Text that was deleted from a document
details	style, open	Interactive widget with text visible only when toggled to 'open' state
dl	style	Description list
dt	style	Term or value in a description list
em	style	Emphasized text (typically displayed in italic)
font	style, color, size, face	Text with specified font properties (obsolete in HTML5)
footer	style	Footer
h1. h2, h3, h4, h5, h6	style	Section heading — <h1> is the highest level of heading and <h6> is the lowest
header	style	Introductory content
hr	style	Thematic break
i	style	Text offset from the surrounding content — by default rendered as italic
ins	style, datetime	Text inserted into a document
li	style	Item in a list
mark	style	Marked or highlighted text
ol	style	Ordered list
p	style	Paragraph
pre	style	Preformatted text
s	style	Text with a strikethrough
strike	style	Text with a strikethrough (obsolete in HTML5)
section	style	Standalone section
small	style	Text one font size level smaller than surrounding text (obsolete in HTML5)
sub	style	Subscript
sup	style	Superscript
strong	style	Text with strong importance
table	style, width, border, align, valign	Table
tbody	style, align, valign	Table body
td	style, width, rowspan, colspan, align, valign	Table data cell
tfoot	style, align, valign	Set of table rows that summarize the table columns
th	style, width, rowspan, colspan, align, valign	Table data cell specified as a header of a group of cells
thead	style, align, valign	Set of table rows that specify the column heads
tr	style, rowspan, align, valign	Row of table cells
tt	style	Monospace text (obsolete in HTML5)
u	style	Text with an unarticulated annotation — by default rendered as an underline
ul	style	Unordered list

For more information about these elements, see https://developer.mozilla.org/en-US/docs/Web/HTML/Element.

To use HTML markup to create a hyperlink that runs MATLAB code, see Create Hyperlinks that Run Functions.

You can use HTML style attributes to format HTML content. A style attribute is a string of CSS attributes and their values.

These CSS attributes are supported:

• background-color

• border-bottom

• border-bottom-color

• border-bottom-left-radius

• border-bottom-right-radius

• border-bottom-style

• border-bottom-width

• border-left

• border-left-color

• border-left-style

• border-left-width

• border-radius

• border-right

• border-right-color

• border-right-style

• border-right-width

• border-spacing

• border-style

• border-top

• border-top-color

• border-top-left-radius

• border-top-right-radius

• border-top-style

• border-top-width

• border-width

• color

• direction

• font-family

• font-size

• font-style

• font-weight

• height

• hidden

• line-height

• margin

• margin-bottom

• margin-left

• margin-right

• margin-top

• max-height

• max-width

• min-height

• min-width

• overflow

• overflow-wrap

• overflow-x

• overflow-y

• padding

• padding-bottom

• padding-left

• padding-right

• padding-top

• text-align

• text-anchor

• text-decoration

• text-indent

• text-overflow

• text-shadow

• text-transform

• title

• translate

• white-space

• width

For more information about these attributes, see https://developer.mozilla.org/en-US/docs/Web/CSS/Reference.

Version History

Introduced in R2016a

R2021b: Style text and display equations

Use the Interpreter name-value argument to enable markup in the dialog box text. Specify the interpreter as 'html', 'latex', 'tex', or 'none'.