A byte array is a collection of contiguous bytes, which are datum most often made of eight single-bit units. That is, a byte contains a sequence of eight bits and a byte array contains a sequence of groupings of those eight-bit groupings.<\/p>\n
Byte arrays are often used to send data over networks in byte streams<\/a>. This information format ensures maximal system compatibility and relies on end systems, rather than network infrastructure, to decode data.<\/p>\n Byte arrays offer the advantage of allowing access to individual bytes within a larger collection. This affords developers easy access to inspection, often at the sacrifice of performance and memory overhead. For non-real-time conditions, this isn’t a practical concern but should be kept in mind.<\/p>\n For example, inserting new values into a\u00a0mutable<\/em> byte array object is somewhat inefficient. However,\u00a0looking up values<\/em> is very efficient as is deriving attributes such as size, length, or specific positioning of elements.<\/p>\n Bytes are often assumed to contain 8 bits\u2014this is not guaranteed, but practical. Byte streams could contain sequences of 16-bits, 32-bits, or some other arbitrary value chosen by developers. Eight-bit sequences are conventional enough to\u00a0make an assumption\u00a0<\/em>but not conventional enough to make a guarantee<\/em>.<\/strong><\/p>\n Eight-bit bytes can represent values up to 256 which limits the encodings that are available. For example, the ASCII character set<\/a> contains values represented by 0-128.<\/p>\n In eight-bit representations of numbers, a maximum value of 256 is possible indicating that ASCII falls short of full utilization of possible characters. The ISO 8859-1 (Latin-1) standard<\/a> established a full 256-character set to make full use of the range of values afforded by the 8-bit byte convention.<\/p>\n The representation of 256 characters makes the assumption that all values are positively signed. For positive and negatively signed values, a byte array can still represent a range of 256 values, but that range shifts from 0-256 to -127\u2014127 where the first bit represents the sign (two’s complement.)<\/p>\n Encoding, decoding, and the use of different character sets are common among programming. These considerations are particularly prevalent among network programming applications, such as TCP\/IP transfer protocol<\/a>. Modern programming languages like Python, Java, and C++<\/a> all provide tools for developers to specify, convert, and manipulate data such that binary data can be appropriately interpreted. For example, Python has built-in functions for converting data to ASCII<\/a> and Java has a powerful Sockets library that handles binary data transfer<\/a>.<\/p>\nUse-Cases<\/h2>\n
Important Considerations<\/h2>\n