Create SHA-256 Hashes Online Generate SHA-256 hash digests.

The tool uses the SubtleCrypto API when available to generate the SHA-256 hash, specifically calling `window.crypto.subtle.digest` with 'SHA-256' as the algorithm and a Uint8Array of the input data encoded using TextEncoder. If this is not supported, it falls back to using the crypto-js library, importing its default module and calling `CryptoJS.SHA256` on the input text. The resulting hash value is then converted into a hexadecimal string by mapping each byte in the hash buffer to its corresponding two-digit hex representation.

In terms of data structures, the tool utilizes Uint8Array for storing the encoded input data and the resulting hash buffer. It also employs Array.from to convert the hash buffer into an array that can be mapped over to generate the hexadecimal string. The TextEncoder API is used with UTF-8 encoding scheme to ensure consistent results across different platforms.

The SubtleCrypto API provides a more secure way of generating hashes as it uses the browser's native cryptographic capabilities, which are typically implemented in C or assembly language and thus faster and more secure than JavaScript-based implementations like crypto-js. When using crypto-js, the library itself implements the SHA-256 algorithm according to the FIPS 180-4 standard.

Internally, the tool maintains several states including input text, generated hash value, method used for generation, and a flag indicating whether the hash has been copied to the clipboard. These states are updated dynamically as the user interacts with the tool, such as when typing in the input textarea or clicking on the copy button. The `generateHash` function is memoized using useCallback to prevent unnecessary re-computations of the hash value when the component re-renders.