strings.substring() function

strings.substring() returns a substring based on start and end parameters. These parameters are represent indices of UTF code points in the string.

When start or end are past the bounds of the string, respectively the start or end of the string is assumed. When end is less than or equal to start an empty string is returned.

Function type signature
(end: int, start: int, v: string) => string

For more information, see Function type signatures.



(Required) String value to search for.


(Required) Starting inclusive index of the substring.


(Required) Ending exclusive index of the substring.


Return part of a string based on character index

import "sampledata"
import "strings"

    |> map(fn: (r) => ({r with _value: strings.substring(v: r._value, start: 5, end: 9)}))

View example input and output

Was this page helpful?

Thank you for your feedback!

The future of Flux

Flux is going into maintenance mode. You can continue using it as you currently are without any changes to your code.

Read more