Name
Boolean — support for boolean values
Availability
JavaScript 1.1; JScript 2.0; ECMAScript v1
Inherits from/Overrides
Inherits from Object
Constructor
new Boolean(value
) //Constructor function Boolean(value
) // Conversion function
Arguments
-
value
The value to be held by the Boolean object or to be converted to a boolean value.
Returns
When invoked as a constructor with the new
operator, Boolean( )
converts its argument to a
boolean value and returns a Boolean object that contains that value.
When invoked as a function, without the new
operator, Boolean( )
simply converts its argument
to a primitive boolean value and returns that value.
The values 0, NaN, null
, the empty string
""
, and the undefined
value are
all converted to false
. All other primitive
values, except false
(but including the string
“false”), and all objects and arrays are converted to
true
.
Methods
-
toString( )
Returns
true
orfalse
, depending on the boolean value represented by the Boolean object.-
valueOf( )
Returns the primitive boolean value contained in the Boolean object.
Description
Boolean values are a fundamental data
type in JavaScript. The Boolean object is an object wrapper around
the boolean value. This Boolean object type exists primarily to
provide a toString( )
method to convert boolean
values to strings. When the toString( )
method is
invoked to convert a boolean value to a
string (and it is often invoked implicitly by JavaScript) JavaScript internally converts the boolean value to a transient Boolean ...
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