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| -rw-r--r-- | doc/effective_go.html | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/doc/effective_go.html b/doc/effective_go.html index 740c1cf8e..becfd17b2 100644 --- a/doc/effective_go.html +++ b/doc/effective_go.html @@ -489,10 +489,10 @@ and <code>while</code> and there is no <code>do-while</code>. There are three forms, only one of which has semicolons: </p> <pre> -// Like a C for: +// Like a C for for init; condition; post { } -// Like a C while: +// Like a C while for condition { } // Like a C for(;;) @@ -522,9 +522,28 @@ for key, value := range m { // key is unused; could call it '_' </pre> <p> +For strings, the <code>range</code> does more of the work for you, breaking out individual +characters by parsing the UTF-8 (erroneous encodings consume one byte and produce the +replacement rune U+FFFD). The loop +</p> +<pre> +for pos, char := range "日本語" { + fmt.Printf("character %c starts at byte position %d\n", char, pos) +} +</pre> +<p> +prints +</p> +<pre> +character 日 starts at byte position 0 +character 本 starts at byte position 3 +character 語 starts at byte position 6 +</pre> + +<p> Finally, since Go has no comma operator and <code>++</code> and <code>--</code> are statements not expressions, if you want to run multiple variables in a <code>for</code> -you can use parallel assignment: +you should use parallel assignment: </p> <pre> // Reverse a |