Many classes have shortcut names used when creating (instantiating) a class with a
configuration object. The shortcut name is referred to as an alias
(or xtype
if the
class extends Ext.Component). The alias/xtype is listed next to the class name of
applicable classes for quick reference.
Framework classes or their members may be specified as private
or protected
. Else,
the class / member is public
. Public
, protected
, and private
are access
descriptors used to convey how and when the class or class member should be used.
Public classes and class members are available for use by any other class or application code and may be relied upon as a stable and persistent within major product versions. Public classes and members may safely be extended via a subclass.
Protected class members are stable public
members intended to be used by the
owning class or its subclasses. Protected members may safely be extended via a subclass.
Private classes and class members are used internally by the framework and are not intended to be used by application developers. Private classes and members may change or be omitted from the framework at any time without notice and should not be relied upon in application logic.
static
label next to the
method name. *See Static below.Below is an example class member that we can disect to show the syntax of a class member (the lookupComponent method as viewed from the Ext.button.Button class in this case).
Let's look at each part of the member row:
lookupComponent
in this example)( item )
in this example)Ext.Component
in this case). This may be omitted for methods that do not
return anything other than undefined
or may display as multiple possible values
separated by a forward slash /
signifying that what is returned may depend on the
results of the method call (i.e. a method may return a Component if a get method calls is
successful or false
if unsuccessful which would be displayed as
Ext.Component/Boolean
).PROTECTED
in
this example - see the Flags section below)Ext.container.Container
in this example). The source
class will be displayed as a blue link if the member originates from the current class
and gray if it is inherited from an ancestor or mixed-in class.view source
in the example)item : Object
in the example).undefined
a "Returns" section
will note the type of class or object returned and a description (Ext.Component
in the
example)Available since 3.4.0
- not pictured in
the example) just after the member descriptionDefaults to: false
)The API documentation uses a number of flags to further commnicate the class member's function and intent. The label may be represented by a text label, an abbreviation, or an icon.
classInstance.method1().method2().etc();
false
is returned from
an event handler- Indicates a framework class
- A singleton framework class. *See the singleton flag for more information
- A component-type framework class (any class within the Ext JS framework that extends Ext.Component)
- Indicates that the class, member, or guide is new in the currently viewed version
- Indicates a class member of type config
- Indicates a class member of type property
- Indicates a class member of type
method
- Indicates a class member of type event
- Indicates a class member of type
theme variable
- Indicates a class member of type
theme mixin
- Indicates that the class, member, or guide is new in the currently viewed version
Just below the class name on an API doc page is a row of buttons corresponding to the types of members owned by the current class. Each button shows a count of members by type (this count is updated as filters are applied). Clicking the button will navigate you to that member section. Hovering over the member-type button will reveal a popup menu of all members of that type for quick navigation.
Getting and setter methods that correlate to a class config option will show up in the methods section as well as in the configs section of both the API doc and the member-type menus just beneath the config they work with. The getter and setter method documentation will be found in the config row for easy reference.
Your page history is kept in localstorage and displayed (using the available real estate) just below the top title bar. By default, the only search results shown are the pages matching the product / version you're currently viewing. You can expand what is displayed by clicking on the button on the right-hand side of the history bar and choosing the "All" radio option. This will show all recent pages in the history bar for all products / versions.
Within the history config menu you will also see a listing of your recent page visits. The results are filtered by the "Current Product / Version" and "All" radio options. Clicking on the button will clear the history bar as well as the history kept in local storage.
If "All" is selected in the history config menu the checkbox option for "Show product details in the history bar" will be enabled. When checked, the product/version for each historic page will show alongside the page name in the history bar. Hovering the cursor over the page names in the history bar will also show the product/version as a tooltip.
Both API docs and guides can be searched for using the search field at the top of the page.
On API doc pages there is also a filter input field that filters the member rows using the filter string. In addition to filtering by string you can filter the class members by access level, inheritance, and read only. This is done using the checkboxes at the top of the page.
The checkbox at the bottom of the API class navigation tree filters the class list to include or exclude private classes.
Clicking on an empty search field will show your last 10 searches for quick navigation.
Each API doc page (with the exception of Javascript primitives pages) has a menu view of metadata relating to that class. This metadata view will have one or more of the following:
Ext.button.Button
class has an alternate class name of Ext.Button
). Alternate class
names are commonly maintained for backward compatibility.Runnable examples (Fiddles) are expanded on a page by default. You can collapse and expand example code blocks individually using the arrow on the top-left of the code block. You can also toggle the collapse state of all examples using the toggle button on the top-right of the page. The toggle-all state will be remembered between page loads.
Class members are collapsed on a page by default. You can expand and collapse members using the arrow icon on the left of the member row or globally using the expand / collapse all toggle button top-right.
Viewing the docs on narrower screens or browsers will result in a view optimized for a smaller form factor. The primary differences between the desktop and "mobile" view are:
The class source can be viewed by clicking on the class name at the top of an API doc page. The source for class members can be viewed by clicking on the "view source" link on the right-hand side of the member row.
Creates a wrapper object to allow you to work with numerical values.
The primary uses for the Number
object are:
If the argument cannot be converted into a number, it returns NaN
.
In a non-constructor context (i.e., without the new
operator), Number
can
be used to perform a type conversion.
Number
object to assign values to numeric variablesThe following example uses the Number
object's properties to assign values to
several numeric variables:
biggestNum = Number.MAX_VALUE;
smallestNum = Number.MIN_VALUE;
infiniteNum = Number.POSITIVE_INFINITY;
negInfiniteNum = Number.NEGATIVE_INFINITY;
notANum = Number.NaN;
Number
to convert a Date
objectThe following example converts the Date
object to a numerical value using
Number
as a function:
var d = new Date("December 17, 1995 03:24:00");
print(Number(d));
This displays "819199440000".
The following example converts the Date object to a numerical value using
Number
as a function:
Special value representing negative infinity; returned on overflow.
The value of Number.NEGATIVE_INFINITY
is the same as the negative value of the global object's
Infinity property.
This value behaves slightly differently than mathematical infinity:
Several JavaScript methods (such as the Number
constructor, parseFloat
, and parseInt
) return
NaN
if the value specified in the parameter is significantly lower than Number.MIN_VALUE
.
You might use the Number.NEGATIVE_INFINITY
property to indicate an error condition that returns a
finite number in case of success. Note, however, that isFinite
would be more appropriate in such
a case.
In the following example, the variable smallNumber is assigned a value that is smaller than the
minimum value. When the if
statement executes, smallNumber
has the value "-Infinity"
, so
smallNumber
is set to a more manageable value before continuing.
var smallNumber = (-Number.MAX_VALUE) * 2
if (smallNumber == Number.NEGATIVE_INFINITY) {
smallNumber = returnFinite();
}
Special value representing infinity; returned on overflow.
The value of Number.POSITIVE_INFINITY
is the same as the value of the global object's Infinity
property.
This value behaves slightly differently than mathematical infinity:
Several JavaScript methods (such as the Number
constructor, parseFloat
, and parseInt
) return
NaN
if the value specified in the parameter is significantly higher than Number.MAX_VALUE
.
You might use the Number.POSITIVE_INFINITY
property to indicate an error condition that returns a
finite number in case of success. Note, however, that isFinite
would be more appropriate in such
a case.
In the following example, the variable bigNumber
is assigned a value that is larger than the
maximum value. When the if statement executes, bigNumber
has the value "Infinity", so bigNumber
is set to a more manageable value before continuing.
var bigNumber = Number.MAX_VALUE * 2
if (bigNumber == Number.POSITIVE_INFINITY) {
bigNumber = returnFinite();
}
The largest positive representable number. The largest negative representable
number is -MAX_VALUE
.
The MAX_VALUE
property has a value of approximately 1.79E+308. Values larger than MAX_VALUE
are
represented as "Infinity"
.
Because MAX_VALUE
is a static property of Number
, you always use it as Number.MAX_VALUE
,
rather than as a property of a Number
object you created.
The following code multiplies two numeric values. If the result is less than or equal to
MAX_VALUE
, the func1
function is called; otherwise, the func2
function is called.
if (num1 * num2 <= Number.MAX_VALUE)
func1();
else
func2();
The smallest positive representable number -- that is, the positive number
closest to zero (without actually being zero). The smallest negative
representable number is -MIN_VALUE
.
The MIN_VALUE
property is the number closest to 0, not the most negative number, that JavaScript
can represent.
MIN_VALUE
has a value of approximately 5e-324. Values smaller than MIN_VALUE
("underflow
values") are converted to 0.
Because MIN_VALUE
is a static property of Number
, you always use it as Number.MIN_VALUE
,
rather than as a property of a Number
object you created.
The following code divides two numeric values. If the result is greater than or equal to
MIN_VALUE
, the func1
function is called; otherwise, the func2
function is called.
if (num1 / num2 >= Number.MIN_VALUE)
func1()
else
func2()
Creates new Number object.
value : Object
The numeric value of the object being created.
Returns a string representing the number in exponential notation.
A string representing a Number
object in exponential notation with one digit before the decimal
point, rounded to fractionDigits
digits after the decimal point. If the fractionDigits
argument
is omitted, the number of digits after the decimal point defaults to the number of digits necessary
to represent the value uniquely.
If you use the toExponential
method for a numeric literal and the numeric literal has no exponent
and no decimal point, leave a space before the dot that precedes the method call to prevent the dot
from being interpreted as a decimal point.
If a number has more digits that requested by the fractionDigits
parameter, the number is rounded
to the nearest number represented by fractionDigits
digits. See the discussion of rounding in the
description of the toFixed
method, which also applies to toExponential
.
var num=77.1234;
alert("num.toExponential() is " + num.toExponential()); //displays 7.71234e+1
alert("num.toExponential(4) is " + num.toExponential(4)); //displays 7.7123e+1
alert("num.toExponential(2) is " + num.toExponential(2)); //displays 7.71e+1
alert("77.1234.toExponential() is " + 77.1234.toExponential()); //displays 7.71234e+1
alert("77 .toExponential() is " + 77 .toExponential()); //displays 7.7e+1
fractionDigits : Number
An integer specifying the number of digits after the decimal point. Defaults to as many digits as necessary to specify the number.
Exponential notation of number.
Returns a string representing the number in fixed-point notation.
digits : Number
The number of digits to appear after the decimal point; this may be a value between 0 and 20, inclusive, and implementations may optionally support a larger range of values. If this argument is omitted, it is treated as 0.
A string representation of number
that does not use
exponential notation and has exactly digits
digits after the decimal place.
The number is rounded if necessary, and the fractional part is padded with
zeros if necessary so that it has the specified length. If number
is greater
than 1e+21, this method simply calls Number.toString()
and returns a string
in exponential notation.
Returns a human readable string representing the number using the locale of the
environment. Overrides the Object.prototype.toLocaleString
method.
This method available to numbers will convert the number into a string which is suitable for presentation in the given locale.
var number = 3500
console.log(number.toLocaleString()); // Displays "3,500" in English locale
String representing the number.
Returns a string representing the number to a specified precision in fixed- point or exponential notation.
A string representing a Number
object in fixed-point or
exponential notation rounded to precision significant digits. See the
discussion of rounding in the description of the toFixed
method, which also
applies to toPrecision
.
If the precision argument is omitted, behaves as Number.toString. If it is a non-integer value, it is rounded to the nearest integer. After rounding, if that value is not between 1 and 100 (inclusive), a RangeError is thrown.
precision : Number
An integer specifying the number of significant digits.
String that represents Number
object.
Returns a string representing the specified object. Overrides the
Object.prototype.toString
method.
The Number
object overrides the toString
method of the Object
object; it does not inherit
Object.toString
. For Number
objects, the toString method returns a string representation of the
object in the specified radix.
The toString
method parses its first argument, and attempts to return a string representation in
the specified radix (base). For radixes above 10, the letters of the alphabet indicate numerals
greater than 9. For example, for hexadecimal numbers (base 16), A through F are used.
If toString
is given a radix not between 2 and 36, an exception is thrown.
If the radix is not specified, JavaScript assumes the preferred radix is 10.
var count = 10;
print(count.toString()); // displays "10"
print((17).toString()); // displays "17"
var x = 7;
print(x.toString(2)); // displays "111"
radix : Number
An integer between 2 and 36 specifying the base to use for representing numeric values.
The number represented as a string.
Returns the primitive value of the specified object. Overrides the
Object.prototype.valueOf
method.
The valueOf
method of Number
returns the primitive value of a Number
object as a number data
type.
This method is usually called internally by JavaScript and not explicitly in code.
var x = new Number();
print(x.valueOf()); // prints "0"
The primitive value of the number.