docs-v2/content/v2.0/reference/flux/functions/strings/substring.md

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---
title: strings.substring() function
description: >
The strings.substring() function returns a substring based on `start` and `end` parameters.
Indices are based on UTF code points.
menu:
v2_0_ref:
name: strings.substring
parent: Strings
weight: 301
---
The `strings.substring()` function returns a substring based on `start` and `end` parameters.
These parameters are represent indices of UTF code points in the string.
_**Output data type:** String_
```js
import "strings"
strings.substring(v: "influx", start: 0, end: 3)
// returns "infl"
```
## Parameters
### v
The string value to search.
_**Data type:** String_
### start
The starting index of the substring.
_**Data type:** Integer_
### end
The ending index of the substring.
_**Data type:** Integer_
## Examples
###### Store the first four characters of a string
```js
import "strings"
data
|> map(fn: (r) => ({
r with
abbr: strings.substring(v: r.name, start: 0, end: 3)
})
)
```