The Go Programming Language

5.3 Multiple Return Values

A function can return more than one result. We’ve seen many examples of functions from standard packages that return two values, the desired computational result and an error value or boolean that indicates whether the computation worked. The next example shows how to write one of our own.

The program below is a variation of findlinks that makes the HTTP request itself so that we no longer need to run fetch. Because the HTTP and parsing operations can fail, findLinks declares two results: the list of discovered links and an error. Incidentally, the HTML parser can usually recover from bad input and construct a document containing error nodes, so Parse rarely fails; when it does, it’s typically due to underlying ...