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Diffstat (limited to 'doc/go_tutorial.html')
| -rw-r--r-- | doc/go_tutorial.html | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/doc/go_tutorial.html b/doc/go_tutorial.html index 77ceb3541..bbd87bb61 100644 --- a/doc/go_tutorial.html +++ b/doc/go_tutorial.html @@ -1,4 +1,4 @@ -<!-- Let's Go --> +<!-- A Tutorial for the Go Programming Language --> <h2>Introduction</h2> <p> This document is a tutorial introduction to the basics of the Go programming @@ -340,6 +340,24 @@ The built-in function <code>len()</code>, which returns number of elements, makes its first appearance in <code>sum</code>. It works on strings, arrays, slices, maps, and channels. <p> +By the way, another thing that works on strings, arrays, slices, maps +and channels is the <code>range</code> clause on <code>for</code> loops. Instead of writing +<p> +<pre> + for i := 0; i < len(a); i++ { ... } +</pre> +<p> +to loop over the elements of a slice (or map or ...) , we could write +<p> +<pre> + for i, v := range a { ... } +</pre> +<p> +This assigns <code>i</code> to the index and <code>v</code> to the value of the successive +elements of the target of the range. See +<a href='/doc/effective_go.html'>Effective Go</a> +for more examples of its use. +<p> <p> <h2>An Interlude about Allocation</h2> <p> @@ -511,7 +529,7 @@ exported factory to use is <code>Open</code>: </pre> <p> There are a number of new things in these few lines. First, <code>Open</code> returns -multiple values, an <code>File</code> and an error (more about errors in a moment). +multiple values, a <code>File</code> and an error (more about errors in a moment). We declare the multi-value return as a parenthesized list of declarations; syntactically they look just like a second parameter list. The function |