content/flux/v0/stdlib/strings/substring.md
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.
(end: int, start: int, v: string) => string
{{% caption %}} For more information, see Function type signatures. {{% /caption %}}
({{< req >}}) String value to search for.
({{< req >}}) Starting inclusive index of the substring.
({{< req >}}) Ending exclusive index of the substring.
import "sampledata"
import "strings"
sampledata.string()
|> map(fn: (r) => ({r with _value: strings.substring(v: r._value, start: 5, end: 9)}))
{{< expand-wrapper >}} {{% expand "View example input and output" %}}
| _time | *tag | _value |
|---|---|---|
| 2021-01-01T00:00:00Z | t1 | smpl_g9qczs |
| 2021-01-01T00:00:10Z | t1 | smpl_0mgv9n |
| 2021-01-01T00:00:20Z | t1 | smpl_phw664 |
| 2021-01-01T00:00:30Z | t1 | smpl_guvzy4 |
| 2021-01-01T00:00:40Z | t1 | smpl_5v3cce |
| 2021-01-01T00:00:50Z | t1 | smpl_s9fmgy |
| _time | *tag | _value |
|---|---|---|
| 2021-01-01T00:00:00Z | t2 | smpl_b5eida |
| 2021-01-01T00:00:10Z | t2 | smpl_eu4oxp |
| 2021-01-01T00:00:20Z | t2 | smpl_5g7tz4 |
| 2021-01-01T00:00:30Z | t2 | smpl_sox1ut |
| 2021-01-01T00:00:40Z | t2 | smpl_wfm757 |
| 2021-01-01T00:00:50Z | t2 | smpl_dtn2bv |
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | g9qc | t1 |
| 2021-01-01T00:00:10Z | 0mgv | t1 |
| 2021-01-01T00:00:20Z | phw6 | t1 |
| 2021-01-01T00:00:30Z | guvz | t1 |
| 2021-01-01T00:00:40Z | 5v3c | t1 |
| 2021-01-01T00:00:50Z | s9fm | t1 |
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | b5ei | t2 |
| 2021-01-01T00:00:10Z | eu4o | t2 |
| 2021-01-01T00:00:20Z | 5g7t | t2 |
| 2021-01-01T00:00:30Z | sox1 | t2 |
| 2021-01-01T00:00:40Z | wfm7 | t2 |
| 2021-01-01T00:00:50Z | dtn2 | t2 |
{{% /expand %}} {{< /expand-wrapper >}}