docs-v2/content/flux/v0.x/stdlib/strings/isupper.md

title	description	menu	weight
strings.isUpper() function	`strings.isUpper()` tests if a single character string is uppercase.	flux_0_x_ref name parent identifier strings.isUpper strings strings/isUpper	101

strings.isUpper() tests if a single character string is uppercase.

Function type signature

(v: string) => bool

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

Parameters

v

({{< req >}}) Single-character string value to test.

Examples

Filter by columns with single-letter uppercase values

import "strings"

data
    |> filter(fn: (r) => strings.isUpper(v: r._value))

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

Input data

_time	*tag	_value
2022-01-01T00:00:00Z	t1	a
2022-01-01T00:01:00Z	t1	B
2022-01-01T00:02:00Z	t1	C
2022-01-01T00:03:00Z	t1	d
2022-01-01T00:04:00Z	t1	e

_time	*tag	_value
2022-01-01T00:00:00Z	t2	F
2022-01-01T00:01:00Z	t2	g
2022-01-01T00:02:00Z	t2	H
2022-01-01T00:03:00Z	t2	i
2022-01-01T00:04:00Z	t2	J

Output data

_time	*tag	_value
2022-01-01T00:01:00Z	t1	B
2022-01-01T00:02:00Z	t1	C

_time	*tag	_value
2022-01-01T00:00:00Z	t2	F
2022-01-01T00:02:00Z	t2	H
2022-01-01T00:04:00Z	t2	J

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