Pop-11 A vector class is a class of data whose instances may be of different lengths, though once an instance is created, its length cannot be changed. Pop-11 includes two main built in vector classes, namely strings and vectors. A string is an instance of a vector class that is constrained to contain an ordered set of characters, i.e. 8-bit integers. Strings may be of different lengths, but each component of a string must be an 8-bit character. E.g. 'a tiny string' 'a much longer string of characters' Ordinary Pop-11 vectors can also be of different lengths, but their contents are unconstrained.
Vectors play a major role in the construction of arrays.
However it is often simpler to use the vectorclass construct. Example of creation of a new vector class. By default the number 0 is put into each of the fields of a newly created short vector. Attempting to assign something else will cause an error. Similarly for strings the corresponding procedures are inits, consstring, isstring, subscrs, deststring.