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Label Properties

Control label appearance

Labels are UI components that contain static text for labelling parts of an app. Properties control the appearance and behavior of a label. Use dot notation to refer to a specific object and property.

fig = uifigure;
tlabel = uilabel(fig);
tlabel.Text = 'Options';

Text

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Label text, specified as a character vector, cell array of character vectors, string scalar, string array, or 1-D categorical array. Use a cell array of character vectors or a string array to specify multiple lines of text.

Alternatively, use the sprintf function to create formatted text containing line breaks and other special characters.

text = sprintf('%s\n%s','Line 1','Line 2');
label = uilabel('Text',text,'Position',[100 100 100 32]);

If you specify text as a character vector without using sprintf, MATLAB® will not interpret control sequences such as \n.

If you specify this property as a categorical array, MATLAB uses the values in the array, not the full set of categories.

Example: 'Threshold'

Example: {'Threshold' 'Value'}

Label 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.

ModifierDescriptionExample
^{ }Superscript'text^{superscript}'
_{ }Subscript'text_{subscript}'
\bfBold font'\bf text'
\itItalic font'\it text'
\slOblique font (usually the same as italic font)'\sl text'
\rmNormal 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 SequenceSymbolCharacter SequenceSymbolCharacter SequenceSymbol

\alpha

α

\upsilon

υ

\sim

~

\angle

\phi

\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

\neq

\equiv

\oplus

\aleph

\Im

\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

To use LaTeX markup, set the interpreter to 'latex'. 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. The FontName, FontWeight, and FontAngle label properties do not have an effect. To change the font style, use LaTeX markup.

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

HTML Markup

To use HTML markup, set the interpreter to 'html'. Setting font styles via HTML overrides any equivalent Label font properties. For example, the following code results in red text.

lbl = uilabel('Interpreter','html');
lbl.Text = '<p style="color: red;">Text</p>');
lbl.FontColor = 'blue';

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 ElementAttributesDescription
astyle, target, href, titleHyperlink
abbrstyle, titleAbbreviation or acronym
addressstyleContact information
articlestyleSelf-contained, independent content
asidestyleContent indirectly related to the main content
bstyleBold text
bdistyle, dirContent formatted in a different direction from surrounding text
bdostyle, dirContent formatted in a different direction from surrounding text
bigstyleText one font size level larger than surrounding text (obsolete in HTML5)
blockquotestyle, citeExtended quotation
brn/aLine break
captionstyleCaption or title of a table
centerstyleContent centered horizontally
citestyleTitle of a creative work
codestyleFragment of code
colstyle, align, valign, span, widthColumn within a table
colgroupstyle, align, valign, span, widthGroup of columns within a table
ddstyleTerm or value in a description list
delstyle, datetimeText that was deleted from a document
detailsstyle, openInteractive widget with text visible only when toggled to 'open' state
dlstyleDescription list
dtstyleTerm or value in a description list
emstyleEmphasized text (typically displayed in italic)
fontstyle, color, size, faceText with specified font properties (obsolete in HTML5)
footerstyleFooter
h1. h2, h3, h4, h5, h6styleSection heading — <h1> is the highest level of heading and <h6> is the lowest
headerstyleIntroductory content
hrstyleThematic break
istyleText offset from the surrounding content — by default rendered as italic
insstyle, datetimeText inserted into a document
listyleItem in a list
markstyleMarked or highlighted text
olstyleOrdered list
pstyleParagraph
prestylePreformatted text
sstyleText with a strikethrough
strikestyleText with a strikethrough (obsolete in HTML5)
sectionstyleStandalone section
smallstyleText one font size level smaller than surrounding text (obsolete in HTML5)
substyleSubscript
supstyleSuperscript
strongstyleText with strong importance
tablestyle, width, border, align, valignTable
tbodystyle, align, valignTable body
tdstyle, width, rowspan, colspan, align, valignTable data cell
tfootstyle, align, valignSet of table rows that summarize the table columns
thstyle, width, rowspan, colspan, align, valignTable data cell specified as a header of a group of cells
theadstyle, align, valignSet of table rows that specify the column heads
trstyle, rowspan, align, valignRow of table cells
ttstyleMonospace text (obsolete in HTML5)
ustyleText with an unarticulated annotation — by default rendered as an underline
ulstyleUnordered list

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

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.

Horizontal alignment of the text, specified as:

  • 'right' — Text aligns on the right side of the area specified by the Position property.

  • 'left' — Text aligns on the left side of the area specified by the Position property.

  • 'center'— Text centers horizontally in the area specified by the Position property.

Aligning label text is useful when the text spans multiple lines.

Vertical alignment of the text, specified as one of the following:

  • 'center' — Text centers vertically in the area specified by the Position property.

  • 'top' — Text aligns on the top of the area specified by the Position property.

  • 'bottom' — Text aligns on the bottom of the area specified by the Position property.

Aligning label text is useful when the text spans multiple lines.

Word wrapping to fit component width, specified as 'off' or 'on', or as numeric or logical 0 (false) or 1 (true). A value of 'off' is equivalent to false, and 'on' is equivalent to true. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

Use this property to prevent text from getting clipped horizontally when the width of the component is smaller than the text you want to display.

  • 'off' — Text does not wrap.

  • 'on' — Breaks text into new lines so that each line fits within the width of the component and avoids breaking words when possible.

Setting the WordWrap property to 'on' does not prevent text from getting clipped vertically when the height of the component is too small to display all the lines of text.

Font and Color

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Font name, specified as a system supported font name. The default font depends on the specific operating system and locale.

If the specified font is not available, then MATLAB uses the best match among the fonts available on the system where the app is running.

Example: 'Arial'

Font size, specified as a positive number. The units of measurement are pixels. The default font size depends on the specific operating system and locale.

Example: 14

Font weight, specified as one of these values:

  • 'normal' — Default weight as defined by the particular font

  • 'bold' — Thicker character outlines than 'normal'

Not all fonts have a bold font weight. For fonts that do not, specifying 'bold' results in the normal font weight.

Font angle, specified as 'normal' or 'italic'. Not all fonts have an italic font angle. For fonts that do not, specifying 'italic' results in the normal font angle.

Font color, specified as an RGB triplet, a hexadecimal color code, or one of the options listed in the table.

RGB triplets and hexadecimal color codes are useful for specifying custom colors.

  • An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

  • A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color NameShort NameRGB TripletHexadecimal Color CodeAppearance
'red''r'[1 0 0]'#FF0000'

Sample of the color red

'green''g'[0 1 0]'#00FF00'

Sample of the color green

'blue''b'[0 0 1]'#0000FF'

Sample of the color blue

'cyan' 'c'[0 1 1]'#00FFFF'

Sample of the color cyan

'magenta''m'[1 0 1]'#FF00FF'

Sample of the color magenta

'yellow''y'[1 1 0]'#FFFF00'

Sample of the color yellow

'black''k'[0 0 0]'#000000'

Sample of the color black

'white''w'[1 1 1]'#FFFFFF'

Sample of the color white

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB TripletHexadecimal Color CodeAppearance
[0 0.4470 0.7410]'#0072BD'

Sample of RGB triplet [0 0.4470 0.7410], which appears as dark blue

[0.8500 0.3250 0.0980]'#D95319'

Sample of RGB triplet [0.8500 0.3250 0.0980], which appears as dark orange

[0.9290 0.6940 0.1250]'#EDB120'

Sample of RGB triplet [0.9290 0.6940 0.1250], which appears as dark yellow

[0.4940 0.1840 0.5560]'#7E2F8E'

Sample of RGB triplet [0.4940 0.1840 0.5560], which appears as dark purple

[0.4660 0.6740 0.1880]'#77AC30'

Sample of RGB triplet [0.4660 0.6740 0.1880], which appears as medium green

[0.3010 0.7450 0.9330]'#4DBEEE'

Sample of RGB triplet [0.3010 0.7450 0.9330], which appears as light blue

[0.6350 0.0780 0.1840]'#A2142F'

Sample of RGB triplet [0.6350 0.0780 0.1840], which appears as dark red

Background color, specified as an RGB triplet, a hexadecimal color code, or one of the color options listed in the table.

For a custom color, specify an RGB triplet or a hexadecimal color code.

  • An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

  • A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color NameShort NameRGB TripletHexadecimal Color CodeAppearance
'red''r'[1 0 0]'#FF0000'

Sample of the color red

'green''g'[0 1 0]'#00FF00'

Sample of the color green

'blue''b'[0 0 1]'#0000FF'

Sample of the color blue

'cyan' 'c'[0 1 1]'#00FFFF'

Sample of the color cyan

'magenta''m'[1 0 1]'#FF00FF'

Sample of the color magenta

'yellow''y'[1 1 0]'#FFFF00'

Sample of the color yellow

'black''k'[0 0 0]'#000000'

Sample of the color black

'white''w'[1 1 1]'#FFFFFF'

Sample of the color white

'none'Not applicableNot applicableNot applicableNo color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB TripletHexadecimal Color CodeAppearance
[0 0.4470 0.7410]'#0072BD'

Sample of RGB triplet [0 0.4470 0.7410], which appears as dark blue

[0.8500 0.3250 0.0980]'#D95319'

Sample of RGB triplet [0.8500 0.3250 0.0980], which appears as dark orange

[0.9290 0.6940 0.1250]'#EDB120'

Sample of RGB triplet [0.9290 0.6940 0.1250], which appears as dark yellow

[0.4940 0.1840 0.5560]'#7E2F8E'

Sample of RGB triplet [0.4940 0.1840 0.5560], which appears as dark purple

[0.4660 0.6740 0.1880]'#77AC30'

Sample of RGB triplet [0.4660 0.6740 0.1880], which appears as medium green

[0.3010 0.7450 0.9330]'#4DBEEE'

Sample of RGB triplet [0.3010 0.7450 0.9330], which appears as light blue

[0.6350 0.0780 0.1840]'#A2142F'

Sample of RGB triplet [0.6350 0.0780 0.1840], which appears as dark red

Data Types: double | char

Interactivity

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State of visibility, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

  • 'on' — Display the object.

  • 'off' — Hide the object without deleting it. You still can access the properties of an invisible UI component.

To make your app start faster, set the Visible property to 'off' for all UI components that do not need to appear at startup.

Visual appearance of the label, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

  • 'on' — Label appears normal

  • 'off' — Label appears dimmed

Tooltip, specified as a character vector, cell array of character vectors, string array, or 1-D categorical array. Use this property to display a message when the user hovers the pointer over the component at run time. The tooltip displays even when the component is disabled. To display multiple lines of text, specify a cell array of character vectors or a string array. Each element in the array becomes a separate line of text. If you specify this property as a categorical array, MATLAB uses the values in the array, not the full set of categories.

Context menu, specified as a ContextMenu object created using the uicontextmenu function. Use this property to display a context menu when you right-click on a component.

Position

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Label location and size, relative to the parent, specified as the vector [left bottom width height]. This table describes each element in the vector.

ElementDescription
leftDistance from the inner left edge of the parent container to the outer left edge of the label
bottomDistance from the inner bottom edge of the parent container to the outer bottom edge of the label
widthDistance between the right and left outer edges of the label
heightDistance between the top and bottom outer edges of the label

The Position values are relative to the drawable area of the parent container. The drawable area is the area inside the borders of the container and does not include the area occupied by decorations such as a menu bar or title.

All measurements are in pixel units.

Example: [100 100 100 20]

Inner location and size of label, specified as [left bottom width height]. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to Position property.

This property is read-only.

Outer location and size of label, returned as [left bottom width height]. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to Position.

Layout options, specified as a GridLayoutOptions object. This property specifies options for components that are children of grid layout containers. If the component is not a child of a grid layout container (for example, it is a child of a figure or panel), then this property is empty and has no effect. However, if the component is a child of a grid layout container, you can place the component in the desired row and column of the grid by setting the Row and Column properties on the GridLayoutOptions object.

For example, this code places a label in the third row and second column of its parent grid.

g = uigridlayout([4 3]);
tlabel = uilabel(g);
tlabel.Layout.Row = 3;
tlabel.Layout.Column = 2;

To make the label span multiple rows or columns, specify the Row or Column property as a two-element vector. For example, this label spans columns 2 through 3:

tlabel.Layout.Column = [2 3];

Callbacks

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Object creation 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 containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Write Callbacks in App Designer.

This property specifies a callback function to execute when MATLAB creates the object. MATLAB initializes all property values before executing the CreateFcn callback. If you do not specify the CreateFcn property, then MATLAB executes a default creation function.

Setting the CreateFcn property on an existing component has no effect.

If you specify this property as a function handle or cell array, you can access the object that is being created using the first argument of the callback function. Otherwise, use the gcbo function to access the object.

Object deletion 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 containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Write Callbacks in App Designer.

This property specifies a callback function to execute when MATLAB deletes the object. MATLAB executes the DeleteFcn callback before destroying the properties of the object. If you do not specify the DeleteFcn property, then MATLAB executes a default deletion function.

If you specify this property as a function handle or cell array, you can access the object that is being deleted using the first argument of the callback function. Otherwise, use the gcbo function to access the object.

Callback Execution Control

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Callback interruption, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

This property determines if a running callback can be interrupted. There are two callback states to consider:

  • The running callback is the currently executing callback.

  • The interrupting callback is a callback that tries to interrupt the running callback.

MATLAB determines callback interruption behavior whenever it executes a command that processes the callback queue. These commands include drawnow, figure, uifigure, getframe, waitfor, and pause.

If the running callback does not contain one of these commands, then no interruption occurs. MATLAB first finishes executing the running callback, and later executes the interrupting callback.

If the running callback does contain one of these commands, then the Interruptible property of the object that owns the running callback determines if the interruption occurs:

  • If the value of Interruptible is 'off', then no interruption occurs. Instead, the BusyAction property of the object that owns the interrupting callback determines if the interrupting callback is discarded or added to the callback queue.

  • If the value of Interruptible is 'on', then the interruption occurs. The next time MATLAB processes the callback queue, it stops the execution of the running callback and executes the interrupting callback. After the interrupting callback completes, MATLAB then resumes executing the running callback.

Note

Callback interruption and execution behave differently in these situations:

  • If the interrupting callback is a DeleteFcn, CloseRequestFcn, or SizeChangedFcn callback, then the interruption occurs regardless of the Interruptible property value.

  • If the running callback is currently executing the waitfor function, then the interruption occurs regardless of the Interruptible property value.

  • If the interrupting callback is owned by a Timer object, then the callback executes according to schedule regardless of the Interruptible property value.

Note

When an interruption occurs, MATLAB does not save the state of properties or the display. For example, the object returned by the gca or gcf command might change when another callback executes.

Callback queuing, specified as 'queue' or 'cancel'. The BusyAction property determines how MATLAB handles the execution of interrupting callbacks. There are two callback states to consider:

  • The running callback is the currently executing callback.

  • The interrupting callback is a callback that tries to interrupt the running callback.

The BusyAction property determines callback queuing behavior only when both of these conditions are met:

  • The running callback contains a command that processes the callback queue, such as drawnow, figure, uifigure, getframe, waitfor, or pause.

  • The value of the Interruptible property of the object that owns the running callback is 'off'.

Under these conditions, the BusyAction property of the object that owns the interrupting callback determines how MATLAB handles the interrupting callback. These are possible values of the BusyAction property:

  • 'queue' — Puts the interrupting callback in a queue to be processed after the running callback finishes execution.

  • 'cancel' — Does not execute the interrupting callback.

This property is read-only.

Deletion status, returned as an on/off logical value of type matlab.lang.OnOffSwitchState.

MATLAB sets the BeingDeleted property to 'on' when the DeleteFcn callback begins execution. The BeingDeleted property remains set to 'on' until the component object no longer exists.

Check the value of the BeingDeleted property to verify that the object is not about to be deleted before querying or modifying it.

Parent/Child

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Parent container, specified as a Figure object created using the uifigure function, or one of its child containers: Tab, Panel, ButtonGroup, or GridLayout. If no container is specified, MATLAB calls the uifigure function to create a new Figure object that serves as the parent container.

Visibility of the object handle, specified as 'on', 'callback', or 'off'.

This property controls the visibility of the object in its parent's list of children. When an object is not visible in its parent's list of children, it is not returned by functions that obtain objects by searching the object hierarchy or querying properties. These functions include get, findobj, clf, and close. Objects are valid even if they are not visible. If you can access an object, you can set and get its properties, and pass it to any function that operates on objects.

HandleVisibility ValueDescription
'on'The object is always visible.
'callback'The object is visible from within callbacks or functions invoked by callbacks, but not from within functions invoked from the command line. This option blocks access to the object at the command-line, but allows callback functions to access it.
'off'The object is invisible at all times. This option is useful for preventing unintended changes to the UI by another function. Set the HandleVisibility to 'off' to temporarily hide the object during the execution of that function.

Identifiers

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This property is read-only.

Type of graphics object, returned as 'uilabel'.

Object identifier, specified as a character vector or string scalar. You can specify a unique Tag value to serve as an identifier for an object. When you need access to the object elsewhere in your code, you can use the findobj function to search for the object based on the Tag value.

User data, specified as any MATLAB array. For example, you can specify a scalar, vector, matrix, cell array, character array, table, or structure. Use this property to store arbitrary data on an object.

If you are working in App Designer, create public or private properties in the app to share data instead of using the UserData property. For more information, see Share Data Within App Designer Apps.

See Also

Functions

Introduced in R2016a