---
title: len
description: Returns the length of a string, slice, map, or collection.
categories: [functions]
keywords: []
menu:
  docs:
    parent: functions
function:
  aliases: []
  returnType: int
  signatures: [len INPUT]
relatedFunctions:
  - len
  - strings.Count
  - strings.CountRunes
  - strings.CountWords
  - strings.RuneCount
aliases: [/functions/len]
---

{{% readfile file="/functions/_common/go-template-functions.md" %}}

With a string:

```go-html-template
{{ "ab" | len }} → 2
{{ "" | len }} → 0
```

With a slice:

```go-html-template
{{ slice "a" "b" | len }} → 2
{{ slice | len }} → 0
```

With a map:

```go-html-template
{{ dict "a" 1 "b" 2  | len }} → 2
{{ dict | len }} → 0
```

With a collection:

```go-html-template
{{ site.RegularPages | len }} → 42
```

You may also determine the number of pages in a collection with:

```go-html-template
{{ site.RegularPages.Len }} → 42
```