# subscript(_:) Returns a 32-bit or 64-bit word of this value’s binary representation. ``` subscript(wordIndex: Int) -> UInt { get } ``` ## Parameters `wordIndex` A nonnegative zero-based offset. ## Overview The words are ordered from least significant to most significant, with an infinite sign extension. Negative values are in two’s complement. ``` let negative: StaticBigInt = -0x0011223344556677_8899AABBCCDDEEFF negative.signum() //-> -1 negative.bitWidth //-> 118 negative[0] //-> 0x7766554433221101 negative[1] //-> 0xFFEEDDCCBBAA9988 negative[2] //-> 0xFFFFFFFFFFFFFFFF let positive: StaticBigInt = 0x0011223344556677_8899AABBCCDDEEFF positive.signum() //-> +1 positive.bitWidth //-> 118 positive[0] //-> 0x8899AABBCCDDEEFF positive[1] //-> 0x0011223344556677 positive[2] //-> 0x0000000000000000 ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)