isFinite()

isFinite(value): boolean

Checks if value is a finite primitive number.

DEPRECATED

Use Number.isFinite() directly instead.

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Parameters

value: unknown

The value to check.

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Returns: boolean

true if value is a finite number, false otherwise.

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See Also

• Number.isFinite() - MDN
• Browser support - Can I Use

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Since

2.0.0

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Example

// ❌ Deprecated approach
isFinite(3);        // => true
isFinite(Infinity); // => false
isFinite(NaN);      // => false

// ✅ Recommended approach
Number.isFinite(3);        // => true
Number.isFinite(Infinity); // => false
Number.isFinite(NaN);      // => false

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How it works?

Checks if value is a finite number. Deprecated: Use Number.isFinite() directly (ES2015).

Native Equivalent

// ❌ isFinite(value)
// ✅ Number.isFinite(value)

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Use Cases

Check finite number 📌

Verify a number is finite (not Infinity or NaN).

#finite#number#validate#check

Number.isFinite(42);       // => true
Number.isFinite(Infinity); // => false
Number.isFinite(NaN);      // => false

Validate calculation result

Ensure calculation didn't overflow.

#validate#calculation#overflow

const result = 1 / x;
if (Number.isFinite(result)) {
  // Safe to use
}

Filter valid numbers

Remove infinite values.

#filter#valid#numbers

const nums = [1, Infinity, 3, -Infinity, 5];
nums.filter(Number.isFinite);
// => [1, 3, 5]