# list.indexOf · Rell standard library · Chromia Docs (concept)

> pure function indexOf(value: T): integer Deprecated (for removal): Use 'index_of' instead Search for the first occurrence of the specified element within t

Source: https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/list/index-of/

FUNCTION

# list.indexOf

```signature
pure function indexOf(value: T): integer
```

**Deprecated** (for removal): Use 'index\_of' instead

Search for the first occurrence of the specified element within this list.

**Parameters**

* **value** — the element for which to search

**Returns**

the index of the first occurrence of the element within this list, or `-1` if the element
does not occur in this list

Since 0.9.0

**Alias of** [list.index\_of](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/list/index_of/)

[View this page on docs.chromia.com](https://docs.chromia.com/pages/rell-stdlib/-rell%20-system%20-library/%5Broot%5D/list/index-of.html)Generated API reference, mirrored from the live docs