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Also known as 32-bit Unicode Transformation Format, Unicode Transformation Format – 32-bit, Unicode Transformation Format - 32-bit, UTF32, UTF_32, UCS-4, UCS4

UTF-32 (32-bit Unicode Transformation Format), sometimes called UCS-4, is a fixed-length encoding used to encode Unicode code points that uses exactly 32 bits (four bytes) per code point (but a number of leading bits must be zero as there are far fewer than 232 Unicode code points, needing actually only 21 bits). In contrast, all other Unicode transformation formats are variable-length encodings. Each 32-bit value in UTF-32 represents one Unicode code point and is exactly equal to that code point's numerical value.

Described at

UTF-32 - IBM Documentation

IBM Documentation.

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Note: This feedback goes to your product's documentation team and does not include a response. Issues that require a response should go through IBM support. Note: This feedback goes to your product's documentation team and does not include a response. Issues that require a response should go through IBM support. Note: This feedback goes to your product's documentation team and does not include a response. Issues that require a response should go through IBM support. There has been an error sending your feedback to the team. Your comment was saved locally, if not in an incognito browser, and will be available when attempting to submit feedback again. The IBM® i operating system does not support UTF-32 encoding with a CCSID value. Unicode was originally designed as a pure 16-bit encoding, aimed at representing all modern scripts. Over time, and especially after the addition of over 14 500 composite characters for compatibility with established sets, it became clear that 16 bits were not sufficient for many users. Out of this arose UTF-32. Arrow rightDifferent encodings of Unicode is the algorithmic mapping from every Unicode value to a unique byte sequence.") While IBM values the use of inclusive language, terms that are outside of IBM's direct influence, for the sake of maintaining user understanding, are sometimes required. As other industry leaders join IBM in embracing the use of inclusive language, IBM will continue to update the documentation to reflect those changes.

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Article · 中文

UTF-32是32位Unicode转换格式(Unicode Transformation Formats, 或UTF)的缩写。UTF-32是一种用于编码Unicode的协定,该协定使用32位比特对每个Unicode码位进行编码(但前导比特数必须为零,故仅能表示231个Unicode码位)。与其他可变长度的Unicode转换格式(UTF)相比,UTF-32编码长度是固定的,UTF-32中的每个32位值代表一个Unicode码位,并且与该码位的数值完全一致。 UTF-32的主要优点是可以直接由Unicode码位来索引。在编码序列中查找第N个编码是一个常数时间操作。相比之下,其他可变长度编码需要进行循序存取操作才能在编码序列中找到第N个编码。这使得在计算机程序设计中,编码序列中的字符位置可以用一个整数来表示,整数加一即可得到下一个字符的位置,就和ASCII字符串一样简单。 UTF-32的主要缺点是每个码位使用四个字节,空间浪费较多。在大多数文本中,非基本多文種平面的字符非常罕见,这使得UTF-32所需空间接近UTF-16的两倍和UTF-8的四倍(具体取决于文本中ASCII字符的比例)。 尽管每一個碼位使用固定長度的位元組看似方便,但UTF-32並不如其它Unicode編碼使用廣泛。與UTF-8及UTF-16相比,UTF-32更容易遭到截斷。即使使用了"定寬"字型,在大多数情况下用UTF-32計算顯示字串的寬度也并不比其他编码更加容易。主要原因是,存在著一個字符位置會有多於一種可能的碼點()或一個碼點用多於一個字符位置(如CJK表意字符)。結合符號也意味著,文書編輯者不能將一個码位視同一個編輯上的單位。

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