Bicep logical operators

The logical operators evaluate boolean values, return non-null values, or evaluate a conditional expression. To run the examples, use Azure CLI or Azure PowerShell to deploy a Bicep file.

And &&

operand1 && operand2

Determines if both values are true.

Operands

Return value

True when both values are true, otherwise false is returned.

Example

Evaluates a set of parameter values and a set of expressions.

param operand1 bool = true
param operand2 bool = true

output andResultParm bool = operand1 && operand2
output andResultExp bool = 10 >= 10 && 5 > 2

Output from the example:

To avoid The language expression property 'foo' doesn't exist exception with Bicep objects, you can use the And logical operator as shown in the following example:

param objectToTest object = {
  one: 1
  two: 2
  three: 3
}

output bar bool = contains(objectToTest, 'four') && objectToTest.four == 4

Or ||

operand1 || operand2

Determines if either value is true.

Operands

Return value

True when either value is true, otherwise false is returned.

Example

Evaluates a set of parameter values and a set of expressions.

param operand1 bool = true
param operand2 bool = false

output orResultParm bool = operand1 || operand2
output orResultExp bool = 10 >= 10 || 5 < 2

Output from the example:

To avoid The language expression property array index 'x' is out of bounds exception, you can use the Or logical operator as shown in the following example:

param emptyArray array = []
param numberArray array = [1, 2, 3]

output foo bool = empty(emptyArray) || emptyArray[0] == 'bar'
output bar bool = length(numberArray) >= 3 || numberArray[3] == 4

Not !

!boolValue

Negates a boolean value.

Operand

Return value

Negates the initial value and returns a boolean. If the initial value is true, then false is returned.

Example

The not operator negates a value. The values can be wrapped with parentheses.

param initTrue bool = true
param initFalse bool = false

output startedTrue bool = !(initTrue)
output startedFalse bool = !initFalse

Output from the example:

Coalesce ??

operand1 ?? operand2

Returns first non-null value from operands.

Operands

Return value

Returns the first non-null value. Empty strings, empty arrays, and empty objects aren't null and an <empty> value is returned.

Example

The output statements return the non-null values. The output type must match the type in the comparison or an error is generated.

param myObject object = {
  isnull1: null
  isnull2: null
  string: 'demoString'
  emptystr: ''
  integer: 10
  }

output nonNullStr string = myObject.isnull1 ?? myObject.string ?? myObject.isnull2
output nonNullInt int = myObject.isnull1 ?? myObject.integer ?? myObject.isnull2
output nonNullEmpty string = myObject.isnull1 ?? myObject.emptystr ?? myObject.string ?? myObject.isnull2

Output from the example:

Conditional expression ? :

condition ? true-value : false-value

Evaluates a condition and returns a value whether the condition is true or false.

Operands

Example

This example evaluates a parameter's initial and returns a value whether the condition is true or false.

param initValue bool = true

output outValue string = initValue ? 'true value' : 'false value'

Output from the example:

Next steps

• To create a Bicep file, see Quickstart: Create Bicep files with Visual Studio Code.
• For information about how to resolve Bicep type errors, see Any function for Bicep.
• To compare syntax for Bicep and JSON, see Comparing JSON and Bicep for templates.
• For examples of Bicep functions, see Bicep functions.