The strcat_array function in Axiom Processing Language (APL) allows you to concatenate the elements of an array into a single string, with an optional delimiter separating each element. This function is useful when you need to transform a set of values into a readable or exportable format, such as combining multiple log entries, tracing IDs, or security alerts into a single output for further analysis or reporting.

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For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

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Usage

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Syntax

strcat_array(array, delimiter)

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Parameters

ParameterTypeDescription
arraydynamicThe array of values to concatenate.
delimiterstringThe string used to separate each element in the concatenated result. Optional. Defaults to an empty string if not specified.

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Returns

A single concatenated string with the array’s elements separated by the specified delimiter.

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Use case example

You can use strcat_array to combine HTTP methods and URLs for a quick summary of unique request paths. Query 
['sample-http-logs']
| take 50
| extend combined_requests = strcat_delim(' ', method, uri)
| summarize requests_list = make_list(combined_requests)
| extend paths = strcat_array(requests_list, ', ')
Run in Playground Output
paths
GET /index, POST /submit, GET /about
This query summarizes unique HTTP method and URL combinations into a single, readable string.