len
Syntax
len INPUT
len
is a built-in function in Go that returns the length of a variable according to its type. From the Go documentation:
Array: the number of elements in v.
Pointer to array: the number of elements in *v (even if v is nil).
Slice, or map: the number of elements in v; if v is nil, len(v) is zero.
String: the number of bytes in v.
Channel: the number of elements queued (unread) in the channel buffer; if v is nil, len(v) is zero.
len
is also considered a fundamental function for Hugo templating.
len
Example 1: Longer Headings
You may want to append a class to a heading according to the length of the string therein. The following templating checks to see if the title’s length is greater than 80 characters and, if so, adds a long-title
class to the <h1>
:
<header>
<h1{{if gt (len .Title) 80}} class="long-title"{{end}}>{{.Title}}</h1>
</header>
len
Example 2: Counting Pages with where
The following templating uses where
in conjunction with len
to
figure out the total number of content pages in a posts
section:
{{ $posts := (where .Site.RegularPages "Section" "==" "posts") }}
{{ $postCount := len $posts }}
Note the use of .RegularPages
, a site variable that counts all regular content pages but not the _index.md
pages used to add front matter and content to list templates.