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目录

JavaScript Number isFinite()

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Examples

Is 123 finite?

Number.isFinite(123)
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Number.isFinite("123")
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Description

The Number.isFinite() method returns true if a number is a finite number.

Infinite (not finite) numbers are Infinity, -Infinity, or NaN

Otherwise it returns false.

See Also:

The Global isFinite() Method

The Global isNaN() Method

The Number.isNaN() Method

The POSITIVE_INFINITY Property

The NEGATIVE_INFINITY Property

Difference Between isFinite() and Number.isFinite()

isFinite() returns true if a value is a finite number.

Number.isFinite() returns true if a number is a finite number.

In other words:

isFinite() converts the value to a number before testing it.

Examples

// This returns true
isFinite(123)
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// This returns false
Number.isFinite("123")
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Syntax

Number.isFinite( value)

Parameters

Parameter Description
value Required.
The value to be tested.

Return Value

Type Description
A boolean true if the value is a finite Number, otherwise false.

More Examples

Number.isFinite(+1.23)
Number.isFinite(-1.23)
Number.isFinite('2005/12/12')
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Number.isFinite(5-2)
Number.isFinite(5/2)
Number.isFinite(0)
Number.isFinite(0/0)
Number.isFinite(Infinity)
Number.isFinite(-Infinity)
Number.isFinite(NaN)
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Browser Support

Number.isFinite() is an ECMAScript6 (ES6) feature.

ES6 (JavaScript 2015) is supported in all modern browsers:

Chrome Edge Firefox Safari Opera
Yes Yes Yes Yes Yes

Number.isFinite() is not supported in Internet Explorer 11 (or earlier).

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