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isRegex ​

Checks if a value is a regular expression.

Implementation ​

View Source Code
ts
/**
 * Checks if the provided argument is a regular expression.
 *
 * @example
 * ```ts
 * isRegex(/abc/); // true
 * isRegex(new RegExp('abc')); // true
 * isRegex('abc'); // false
 * isRegex(123); // false
 * isRegex({}); // false
 * isRegex([]); // false
 * isRegex(null); // false
 * isRegex(undefined); // false
 * ```
 *
 * @param arg - The argument to be checked.
 *
 * @return `true` if the argument is a regular expression, otherwise `false`.
 */
export function isRegex(arg: unknown): arg is RegExp {
  return arg instanceof RegExp;
}

API ​

ts
function isRegex(value: unknown): value is RegExp;

Parameters ​

  • value: The value to check

Returns ​

  • true if the value is a RegExp, false otherwise

Examples ​

Basic Usage ​

ts
import { isRegex } from '@vielzeug/toolkit';

isRegex(/abc/); // true
isRegex(new RegExp('abc')); // true
isRegex('abc'); // false

Implementation Notes ​

  • Detects both literal and constructed regular expressions
  • Useful for type guards and validation

See Also ​