toupper

This page explains how to use the toupper function in APL.

The toupper function converts all characters in a string to uppercase. Use this function to normalize text for case-insensitive operations, standardize identifiers, or format strings for emphasis in output.

Usage

Syntax

toupper(value)

Parameters

NameTypeRequiredDescription
valuestringYesThe input string to convert to uppercase.

Returns

Returns the input string with all characters converted to uppercase.

Use case examples

Standardize HTTP status codes and methods for consistent alerting and reporting.

Query

['sample-http-logs']
| extend normalized_method = toupper(method)
| extend alert_status = iff(status startswith '5', toupper(strcat('ERROR_', status)), status)
| summarize request_count = count() by normalized_method, alert_status
| sort by request_count desc
| limit 10

Run in Playground

Output

normalized_methodalert_statusrequest_count
GET2005432
POST2012341
GETERROR_500234

This query normalizes HTTP methods to uppercase and creates emphasized error status codes for critical alerts.

Create uppercase service identifiers for system monitoring and alerting.

Query

['otel-demo-traces']
| extend service_code = toupper(substring(['service.name'], 0, 3))
| summarize span_count = count(), avg_duration = avg(duration) by service_code
| sort by span_count desc
| limit 10

Run in Playground

Output

service_codespan_countavg_duration
FRO4532125ms
CHE3421234ms
CAR298789ms

This query creates three-letter uppercase service codes for compact monitoring displays and alerts.

  • tolower: Converts strings to lowercase. Use this for the opposite transformation.
  • totitle: Converts strings to title case. Use this for capitalized formatting.
  • strcmp: Compares strings. Use toupper before strcmp for case-insensitive comparisons.
  • strcat: Concatenates strings. Use this with toupper to build emphasized messages.

Other query languages