isreal

Use the isreal function to determine whether a value is a real number. This function is helpful when you need to validate data before performing numeric operations. For example, you can use isreal to filter out invalid values which could otherwise disrupt aggregations or calculations.

You often use isreal in data cleaning pipelines, conditional logic, and when inspecting metrics like durations, latencies, or numeric identifiers. It’s especially useful when working with telemetry or log data that includes optional or incomplete numeric fields.

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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

isreal(value)

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Parameters

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Returns

Returns true if the input is a valid real number. Returns false for strings, nulls, or non-numeric types.

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Example

Use isreal to identify real number values.

Query

['sample-http-logs'] 
| extend is_real = isreal(123.11)

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Output

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List of related functions

• ismap: Checks whether a value is of the dynamic type and represents a mapping.
• isstring: Checks whether a value is a string. Use this for scalar string validation.