docs-v2/content/flux/v0/stdlib/universe/string.md

3.5 KiB

title description menu weight flux/v0/tags introduced
string() function `string()` converts a value to a string type.
flux_v0_ref
name parent identifier
string universe universe/string
101
type-conversions
0.7.0

string() converts a value to a string type.

Function type signature
(v: A) => string

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

v

({{< req >}}) Value to convert.

Examples

Convert basic types to strings

string(v: true)
// Returns "true"

string(v: 1m)
// Returns "1m"

string(v: 2021-01-01T00:00:00Z)
// Returns "2021-01-01T00:00:00Z"

string(v: 10.12)
// Returns "10.12"

Convert all values in a column to strings

If converting the _value column to string types, use toString(). If converting columns other than _value, use map() to iterate over each row and string() to convert a column value to a string type.

data
    |> map(fn: (r) => ({r with exampleCol: string(v: r.exampleCol)}))

{{< expand-wrapper >}} {{% expand "View example input and output" %}}

Input data

_time *tag exampleCol
2021-01-01T00:00:00Z t1 -2.18
2021-01-01T00:00:10Z t1 10.92
2021-01-01T00:00:20Z t1 7.35
2021-01-01T00:00:30Z t1 17.53
2021-01-01T00:00:40Z t1 15.23
2021-01-01T00:00:50Z t1 4.43
_time *tag exampleCol
2021-01-01T00:00:00Z t2 19.85
2021-01-01T00:00:10Z t2 4.97
2021-01-01T00:00:20Z t2 -3.75
2021-01-01T00:00:30Z t2 19.77
2021-01-01T00:00:40Z t2 13.86
2021-01-01T00:00:50Z t2 1.86

Output data

_time exampleCol *tag
2021-01-01T00:00:00Z -2.18 t1
2021-01-01T00:00:10Z 10.92 t1
2021-01-01T00:00:20Z 7.35 t1
2021-01-01T00:00:30Z 17.53 t1
2021-01-01T00:00:40Z 15.23 t1
2021-01-01T00:00:50Z 4.43 t1
_time exampleCol *tag
2021-01-01T00:00:00Z 19.85 t2
2021-01-01T00:00:10Z 4.97 t2
2021-01-01T00:00:20Z -3.75 t2
2021-01-01T00:00:30Z 19.77 t2
2021-01-01T00:00:40Z 13.86 t2
2021-01-01T00:00:50Z 1.86 t2

{{% /expand %}} {{< /expand-wrapper >}}