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ToBoolean (Operator/internal)

An internal operator for converting values.

Availability:

ECMAScript edition - 2

This internal operator converts the public types to Boolean values.

The ToBoolean operator converts its argument to a value of type Boolean according to the following table:

Input Type	Result
Undefined	Always `false`.
Null	Always `false`.
Boolean	No conversion, the input value is returned unchanged.
Number	The result is `false` if the argument is `0` or `NaN` otherwise it is `true`.
String	Zero length strings return `false` otherwise the result is `true`.
Object	Always `true`.

See also: Cast operator, Conversion, Implicit conversion, Logical operator, Number, Type conversion

Property attributes:

Internal.

ECMA 262 edition 2 - section - 9.2

ECMA 262 edition 3 - section - 9.2

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JavaScript Programmer's Reference, Cliff Wootton Wrox Press (www.wrox.com) Join the Wrox JavaScript forum at p2p.wrox.com Please report problems to support@wrox.com © 2001 Wrox Press. All Rights Reserved. Terms and conditions.