Mastering Blockchain Programming with Solidity

Fixed size byte arrays

A fixed size array means the array that does not grow or shrink in terms of its capacity. Solidity supports the byte data type that represents a value of a byte (8 bits). There are some predefined byte arrays data types readily available in Solidity: bytes1, bytes2, and so on, up to bytes32 (stepping 1). Each of these is a byte[] arrays type; for example, bytes2 is a byte[2] array of size 2, bytes3 is a byte[3] array of size 3, and so on for bytes32 is a byte[32] array of size 32. bytes1 is a special one, as it is an alias of byte.

As each of bytes1...bytes32 is an array of byte[], their values are accessible with the index. For example, if there is a variable, b, which is of the bytesN type, then b[k] returns the  ...