---
title: in
description: Checks if an element is in an array or slice--or a substring in a string---and returns a boolean.
categories: [functions]
menu:
  docs:
    parent: functions
keywords: [strings]
signature: ["in SET ITEM"]
relatedfuncs: []
---

The elements supported are strings, integers and floats, although only float64 will match as expected.

In addition, `in` can also check if a substring exists in a string.

```go-html-template
{{ if in .Params.tags "Git" }}Follow me on GitHub!{{ end }}
```


```go-html-template
{{ if in "this string contains a substring" "substring" }}Substring found!{{ end }}
```