isBigint()

isBigint(value): value is bigint

Checks if a value is a bigint.

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Parameters

value: unknown

The value to check.

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Returns: value is bigint

true if the value is a bigint, false otherwise.

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Since

1.0.0

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Example

isBigint(123n);  // => true
isBigint(123);   // => false
isBigint('123'); // => false

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How it works?

Type guard that checks if a value is a bigint.

Type Narrowing

Common Checks

Value	Result
123n	true
BigInt(123)	true
123	false
'123'	false
new Object(123n)	false

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Use Cases

Validate large number values 📌

Validate BigInt values for precise calculations. Essential for handling large monetary values or IDs.

#bigint#validation#large numbers#type guard

if (isBigInt(value)) {
  return (value / 100n).toString(); // Safe BigInt operations
}

Handle API responses with mixed types 📌

Handle responses that may contain BigInt values.

#API#response#type guard#parsing

const id = isBigInt(response.id) 
  ? response.id.toString() 
  : String(response.id);

Type-safe arithmetic operations

Ensure type safety before BigInt operations.

#arithmetic#type safety#calculations

if (isBigInt(a) && isBigInt(b)) {
  return a / b; // TypeScript knows both are bigint
}