guardz/dist/typeguards/isNumberKey.d.ts

A simple and lightweight TypeScript type guard library for runtime type validation.

import type { TypeGuardFn } from './isType';
/**
 * Checks if a value is numeric (a number or a string that can be converted to a number).
 *
 * This type guard validates that a value is either a number or a string that can be
 * converted to a number. This is useful for validating numeric values in various contexts
 * like form inputs, API data, object keys, etc.
 *
 * @param value - The value to check
 * @param config - Optional configuration for error handling
 * @returns True if the value is a number or a string that can be converted to a number, false otherwise
 *
 * @example
 * ```typescript
 * import { isNumeric } from 'guardz';
 *
 * console.log(isNumeric(1)); // true
 * console.log(isNumeric("1")); // true
 * console.log(isNumeric("123")); // true
 * console.log(isNumeric("abc")); // false
 * console.log(isNumeric("1.5")); // true
 * console.log(isNumeric("1.0")); // true
 * console.log(isNumeric("0")); // true
 * console.log(isNumeric("")); // false
 * console.log(isNumeric(null)); // false
 * console.log(isNumeric(undefined)); // false
 *
 * // With type narrowing
 * const data: unknown = getDataFromAPI();
 * if (isNumeric(data)) {
 *   // data is now typed as number
 *   console.log(Number(data)); // Safe to convert
 * }
 * ```
 */
export declare const isNumeric: TypeGuardFn<number>;