Logical functions for ARM templates

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

Tip

We recommend Bicep because it offers the same capabilities as ARM templates and the syntax is easier to use. To learn more, see the bool logical function and logical operators.

and

and(arg1, arg2, ...)

Checks whether all parameter values are true.

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

Parameters

Parameter Required Type Description
arg1 Yes boolean The first value to check whether is true.
arg2 Yes boolean The second value to check whether is true.
more arguments No boolean More arguments to check whether are true.

Return value

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

Examples

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:

Name Type Value
andExampleOutput Bool False
orExampleOutput Bool True
notExampleOutput Bool False

bool

bool(arg1)

Converts the parameter to a boolean.

In Bicep, use the bool logical function.

Parameters

Parameter Required Type Description
arg1 Yes string or int The value to convert to a boolean.

Return value

A boolean of the converted value.

Remarks

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

Examples

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:

Name Type Value
trueString Bool True
falseString Bool False
trueInt Bool True
falseInt Bool False

false

false()

Returns false.

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

Parameters

The false function doesn't accept any parameters.

Return value

A boolean that is always false.

Example

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:

Name Type Value
falseOutput Bool False

if

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.

Parameters

Parameter Required Type Description
condition Yes boolean The value to check whether it's true or false.
trueValue Yes string, int, object, or array The value to return when the condition is true.
falseValue Yes string, int, object, or array The value to return when the condition is false.

Return value

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

Remarks

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.

Examples

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:

Name Type Value
yesOutput String yes
noOutput String no
objectOutput Object { "test": "value1" }

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

not(arg1)

Converts boolean value to its opposite value.

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

Parameters

Parameter Required Type Description
arg1 Yes boolean The value to convert.

Return value

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

Examples

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:

Name Type Value
andExampleOutput Bool False
orExampleOutput Bool True
notExampleOutput Bool False

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:

Name Type Value
checkNotEquals Bool True

or

or(arg1, arg2, ...)

Checks whether any parameter value is true.

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

Parameters

Parameter Required Type Description
arg1 Yes boolean The first value to check whether is true.
arg2 Yes boolean The second value to check whether is true.
more arguments No boolean More arguments to check whether are true.

Return value

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

Examples

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:

Name Type Value
andExampleOutput Bool False
orExampleOutput Bool True
notExampleOutput Bool False

true

true()

Returns true.

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

Parameters

The true function doesn't accept any parameters.

Return value

A boolean that is always true.

Example

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:

Name Type Value
trueOutput Bool True

Next steps