linter-rule-prefer-interpolation.md

title	description	ms.topic	ms.custom	ms.date
Linter rule - prefer interpolation	Linter rule - prefer interpolation	conceptual	devx-track-bicep	03/20/2024

Linter rule - prefer interpolation

This rule finds uses of the concat function that can be replaced by string interpolation.

Linter rule code

Use the following value in the Bicep configuration file to customize rule settings:

prefer-interpolation

Solution

Use string interpolation instead of the concat function.

The following example fails this test because the concat function is used.

param suffix string = '001'
var vnetName = concat('vnet-', suffix)

You can fix it by replacing concat with string interpolation. The following example passes this test.

param suffix string = '001'
var vnetName = 'vnet-${suffix}'

Optionally, you can use Quickfix to replace the concat with string interpolation:

:::image type="content" source="./media/linter-rule-prefer-interpolation/linter-rule-prefer-interpolation-quick-fix.png" alt-text="The screenshot of Prefer interpolation linter rule quick fix.":::

Next steps

For more information about the linter, see Use Bicep linter.