Logical functions for ARM templates

Resource Manager provides several functions for making comparisons in your Azure Resource Manager template (ARM template):

• and
• bool
• false
• if
• not
• or
• true

and(arg1, arg2, ...)

Checks whether all parameter values are true.

The and function isn't supported in Bicep. Use the && operator instead.

Returns True if all values are true; otherwise, False.

The following example shows how to use logical functions.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "andExampleOutput": {
      "type": "bool",
      "value": "[and(bool('true'), bool('false'))]"
    },
    "orExampleOutput": {
      "type": "bool",
      "value": "[or(bool('true'), bool('false'))]"
    },
    "notExampleOutput": {
      "type": "bool",
      "value": "[not(bool('true'))]"
    }
  }
}

The output from the preceding example is:

bool(arg1)

Converts the parameter to a boolean.

In Bicep, use the bool logical function.

A boolean of the converted value.

You can also use true() and false() to get boolean values.

The following example shows how to use bool with a string or integer.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "trueString": {
      "type": "bool",
      "value": "[bool('true')]"
    },
    "falseString": {
      "type": "bool",
      "value": "[bool('false')]"
    },
    "trueInt": {
      "type": "bool",
      "value": "[bool(1)]"
    },
    "falseInt": {
      "type": "bool",
      "value": "[bool(0)]"
    }
  }
}

The output from the preceding example with the default values is:

false()

Returns false.

The false function isn't available in Bicep. Use the false keyword instead.

The false function doesn't accept any parameters.

A boolean that is always false.

The following example returns a false output value.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "falseOutput": {
      "type": "bool",
      "value": "[false()]"
    }
  }
}

The output from the preceding example is:

if(condition, trueValue, falseValue)

Returns a value based on whether a condition is true or false.

The if function isn't supported in Bicep. Use the ?: operator instead.

Returns second parameter when first parameter is True; otherwise, returns third parameter.

When the condition is True, only the true value is evaluated. When the condition is False, only the false value is evaluated. With the if function, you can include expressions that are only conditionally valid. For example, you can reference a resource that exists under one condition but not under the other condition. An example of conditionally evaluating expressions is shown in the following section.

The following example shows how to use the if function.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [
  ],
  "outputs": {
    "yesOutput": {
      "type": "string",
      "value": "[if(equals('a', 'a'), 'yes', 'no')]"
    },
    "noOutput": {
      "type": "string",
      "value": "[if(equals('a', 'b'), 'yes', 'no')]"
    },
    "objectOutput": {
      "type": "object",
      "value": "[if(equals('a', 'a'), json('{\"test\": \"value1\"}'), json('null'))]"
    }
  }
}

The output from the preceding example is:

The following example template shows how to use this function with expressions that are only conditionally valid.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "vmName": {
      "type": "string"
    },
    "location": {
      "type": "string"
    },
    "logAnalytics": {
      "type": "string",
      "defaultValue": ""
    }
  },
  "resources": [
    {
      "condition": "[not(empty(parameters('logAnalytics')))]",
      "type": "Microsoft.Compute/virtualMachines/extensions",
      "apiVersion": "2017-03-30",
      "name": "[concat(parameters('vmName'),'/omsOnboarding')]",
      "location": "[parameters('location')]",
      "properties": {
        "publisher": "Microsoft.EnterpriseCloud.Monitoring",
        "type": "MicrosoftMonitoringAgent",
        "typeHandlerVersion": "1.0",
        "autoUpgradeMinorVersion": true,
        "settings": {
          "workspaceId": "[if(not(empty(parameters('logAnalytics'))), reference(parameters('logAnalytics'), '2015-11-01-preview').customerId, json('null'))]"
        },
        "protectedSettings": {
          "workspaceKey": "[if(not(empty(parameters('logAnalytics'))), listKeys(parameters('logAnalytics'), '2015-11-01-preview').primarySharedKey, json('null'))]"
        }
      }
    }
  ],
  "outputs": {
    "mgmtStatus": {
      "type": "string",
      "value": "[if(not(empty(parameters('logAnalytics'))), 'Enabled monitoring for VM!', 'Nothing to enable')]"
    }
  }
}

not(arg1)

Converts boolean value to its opposite value.

The not function isn't supported in Bicep. Use the ! operator instead.

Returns True when parameter is False. Returns False when parameter is True.

The following example shows how to use logical functions.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "andExampleOutput": {
      "type": "bool",
      "value": "[and(bool('true'), bool('false'))]"
    },
    "orExampleOutput": {
      "type": "bool",
      "value": "[or(bool('true'), bool('false'))]"
    },
    "notExampleOutput": {
      "type": "bool",
      "value": "[not(bool('true'))]"
    }
  }
}

The output from the preceding example is:

The following example uses not with equals.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [
  ],
  "outputs": {
    "checkNotEquals": {
      "type": "bool",
      "value": "[not(equals(1, 2))]"
    }
  }
}

The output from the preceding example is:

or(arg1, arg2, ...)

Checks whether any parameter value is true.

The or function isn't supported in Bicep. Use the || operator instead.

Returns True if any value is true; otherwise, False.

The following example shows how to use logical functions.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "andExampleOutput": {
      "type": "bool",
      "value": "[and(bool('true'), bool('false'))]"
    },
    "orExampleOutput": {
      "type": "bool",
      "value": "[or(bool('true'), bool('false'))]"
    },
    "notExampleOutput": {
      "type": "bool",
      "value": "[not(bool('true'))]"
    }
  }
}

The output from the preceding example is:

true()

Returns true.

The true function isn't available in Bicep. Use the true keyword instead.

The true function doesn't accept any parameters.

A boolean that is always true.

The following example returns a true output value.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "resources": [],
  "outputs": {
    "trueOutput": {
      "type": "bool",
      "value": "[true()]"
    }
  }
}

The output from the preceding example is:

• For a description of the sections in an ARM template, see Understand the structure and syntax of ARM templates.