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目录

JavaScript isFinite()

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Examples

Check if a number is finite:

let result = isFinite(123);
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let result = isFinite("123");
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Description

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

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

See Also:

The Number.isFinite() Method

The Global Infinity Property

The Global NaN Property

The Global isNaN() Method

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

isFinite( value)

Parameters

Parameter Description
value Required.
The value to be tested.

Return Value

Type Description
A boolean. false if the value is Infinity, -Infinity, or NaN.
Otherwise true.

More Examples

Check if a number is finite:

isFinite(-1.23);
isFinite(5-2);
isFinite(0);
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isFinite("Hello");
isFinite("2005/12/12");
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Browser Support

isFinite() is an ECMAScript1 (ES1) feature.

ES1 (JavaScript 1997) is fully supported in all browsers:

Chrome Edge Firefox Safari Opera IE
Yes Yes Yes Yes Yes Yes
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