Object functions for ARM templates
Resource Manager provides several functions for working with objects 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 object functions.
contains
contains(container, itemToFind)
Checks whether an array contains a value, an object contains a key, or a string contains a substring. The string comparison is case-sensitive. However, when testing if an object contains a key, the comparison is case-insensitive.
In Bicep, use the contains function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
container | Yes | array, object, or string | The value that contains the value to find. |
itemToFind | Yes | string or int | The value to find. |
Return value
True if the item is found; otherwise, False.
Example
The following example shows how to use contains
with different types:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"stringToTest": {
"type": "string",
"defaultValue": "OneTwoThree"
},
"objectToTest": {
"type": "object",
"defaultValue": {
"one": "a",
"two": "b",
"three": "c"
}
},
"arrayToTest": {
"type": "array",
"defaultValue": [ "one", "two", "three" ]
}
},
"resources": [
],
"outputs": {
"stringTrue": {
"type": "bool",
"value": "[contains(parameters('stringToTest'), 'e')]"
},
"stringFalse": {
"type": "bool",
"value": "[contains(parameters('stringToTest'), 'z')]"
},
"objectTrue": {
"type": "bool",
"value": "[contains(parameters('objectToTest'), 'one')]"
},
"objectFalse": {
"type": "bool",
"value": "[contains(parameters('objectToTest'), 'a')]"
},
"arrayTrue": {
"type": "bool",
"value": "[contains(parameters('arrayToTest'), 'three')]"
},
"arrayFalse": {
"type": "bool",
"value": "[contains(parameters('arrayToTest'), 'four')]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
stringTrue | Bool | True |
stringFalse | Bool | False |
objectTrue | Bool | True |
objectFalse | Bool | False |
arrayTrue | Bool | True |
arrayFalse | Bool | False |
createObject
createObject(key1, value1, key2, value2, ...)
Creates an object from the keys and values.
The createObject
function isn't supported by Bicep. Construct an object by using {}
. See Objects.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
key1 | No | string | The name of the key. |
value1 | No | int, boolean, string, object, or array | The value for the key. |
more keys | No | string | More names of the keys. |
more values | No | int, boolean, string, object, or array | More values for the keys. |
The function only accepts an even number of parameters. Each key must have a matching value.
Return value
An object with each key and value pair.
Example
The following example creates an object from different types of values.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"resources": [
],
"outputs": {
"newObject": {
"type": "object",
"value": "[createObject('intProp', 1, 'stringProp', 'abc', 'boolProp', true(), 'arrayProp', createArray('a', 'b', 'c'), 'objectProp', createObject('key1', 'value1'))]"
}
}
}
The output from the preceding example with the default values is an object named newObject
with the following value:
{
"intProp": 1,
"stringProp": "abc",
"boolProp": true,
"arrayProp": ["a", "b", "c"],
"objectProp": {"key1": "value1"}
}
empty
empty(itemToTest)
Determines if an array, object, or string is empty.
In Bicep, use the empty function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
itemToTest | Yes | array, object, or string | The value to check if it's empty. |
Return value
Returns True if the value is empty; otherwise, False.
Example
The following example checks whether an array, object, and string are empty.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"testArray": {
"type": "array",
"defaultValue": []
},
"testObject": {
"type": "object",
"defaultValue": {}
},
"testString": {
"type": "string",
"defaultValue": ""
}
},
"resources": [
],
"outputs": {
"arrayEmpty": {
"type": "bool",
"value": "[empty(parameters('testArray'))]"
},
"objectEmpty": {
"type": "bool",
"value": "[empty(parameters('testObject'))]"
},
"stringEmpty": {
"type": "bool",
"value": "[empty(parameters('testString'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
arrayEmpty | Bool | True |
objectEmpty | Bool | True |
stringEmpty | Bool | True |
intersection
intersection(arg1, arg2, arg3, ...)
Returns a single array or object with the common elements from the parameters.
In Bicep, use the intersection function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
arg1 | Yes | array or object | The first value to use for finding common elements. |
arg2 | Yes | array or object | The second value to use for finding common elements. |
more arguments | No | array or object | More values to use for finding common elements. |
Return value
An array or object with the common elements.
Example
The following example shows how to use intersection
with arrays and objects.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"firstObject": {
"type": "object",
"defaultValue": {
"one": "a",
"two": "b",
"three": "c"
}
},
"secondObject": {
"type": "object",
"defaultValue": {
"one": "a",
"two": "z",
"three": "c"
}
},
"firstArray": {
"type": "array",
"defaultValue": [ "one", "two", "three" ]
},
"secondArray": {
"type": "array",
"defaultValue": [ "two", "three" ]
}
},
"resources": [
],
"outputs": {
"objectOutput": {
"type": "object",
"value": "[intersection(parameters('firstObject'), parameters('secondObject'))]"
},
"arrayOutput": {
"type": "array",
"value": "[intersection(parameters('firstArray'), parameters('secondArray'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
objectOutput | Object | {"one": "a", "three": "c"} |
arrayOutput | Array | ["two", "three"] |
items
items(object)
Converts a dictionary object to an array. See toObject about converting an array to an object.
In Bicep, use the items.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
object | Yes | object | The dictionary object to convert to an array. |
Return value
An array of objects for the converted dictionary. Each object in the array has a key
property that contains the key value for the dictionary. Each object also has a value
property that contains the properties for the object.
Example
The following example converts a dictionary object to an array. For each object in the array, it creates a new object with modified values.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"variables": {
"copy": [
{
"name": "modifiedListOfEntities",
"count": "[length(items(variables('entities')))]",
"input": {
"key": "[items(variables('entities'))[copyIndex('modifiedListOfEntities')].key]",
"fullName": "[items(variables('entities'))[copyIndex('modifiedListOfEntities')].value.displayName]",
"itemEnabled": "[items(variables('entities'))[copyIndex('modifiedListOfEntities')].value.enabled]"
}
}
],
"entities": {
"item002": {
"enabled": false,
"displayName": "Example item 2",
"number": 200
},
"item001": {
"enabled": true,
"displayName": "Example item 1",
"number": 300
}
}
},
"resources": [],
"outputs": {
"modifiedResult": {
"type": "array",
"value": "[variables('modifiedListOfEntities')]"
}
}
}
The preceding example returns:
"modifiedResult": {
"type": "Array",
"value": [
{
"fullName": "Example item 1",
"itemEnabled": true,
"key": "item001"
},
{
"fullName": "Example item 2",
"itemEnabled": false,
"key": "item002"
}
]
}
The following example shows the array that is returned from the items function.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"variables": {
"entities": {
"item002": {
"enabled": false,
"displayName": "Example item 2",
"number": 200
},
"item001": {
"enabled": true,
"displayName": "Example item 1",
"number": 300
}
},
"entitiesArray": "[items(variables('entities'))]"
},
"resources": [],
"outputs": {
"itemsResult": {
"type": "array",
"value": "[variables('entitiesArray')]"
}
}
}
The example returns:
"itemsResult": {
"type": "Array",
"value": [
{
"key": "item001",
"value": {
"displayName": "Example item 1",
"enabled": true,
"number": 300
}
},
{
"key": "item002",
"value": {
"displayName": "Example item 2",
"enabled": false,
"number": 200
}
}
]
}
In JSON, an object is an unordered collection of zero or more key/value pairs. The ordering can be different depending on the implementations. For example, the Bicep items() function sorts the objects in the alphabetical order. In other places, the original ordering can be preserved. Because of this non-determinism, avoid making any assumptions about the ordering of object keys when writing code, which interacts with deployments parameters & outputs.
json
json(arg1)
Converts a valid JSON string into a JSON data type.
In Bicep, use the json function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
arg1 | Yes | string | The value to convert to JSON. The string must be a properly formatted JSON string. |
Return value
The JSON data type from the specified string, or an empty value when null is specified.
Remarks
If you need to include a parameter value or variable in the JSON object, use the format function to create the string that you pass to the function.
You can also use null() to get a null value.
Example
The following example shows how to use the json
function. Notice that you can pass in null
for an empty object.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"jsonEmptyObject": {
"type": "string",
"defaultValue": "null"
},
"jsonObject": {
"type": "string",
"defaultValue": "{\"a\": \"b\"}"
},
"jsonString": {
"type": "string",
"defaultValue": "\"test\""
},
"jsonBoolean": {
"type": "string",
"defaultValue": "true"
},
"jsonInt": {
"type": "string",
"defaultValue": "3"
},
"jsonArray": {
"type": "string",
"defaultValue": "[[1,2,3 ]"
},
"concatValue": {
"type": "string",
"defaultValue": "demo value"
}
},
"resources": [
],
"outputs": {
"emptyObjectOutput": {
"type": "bool",
"value": "[empty(json(parameters('jsonEmptyObject')))]"
},
"objectOutput": {
"type": "object",
"value": "[json(parameters('jsonObject'))]"
},
"stringOutput": {
"type": "string",
"value": "[json(parameters('jsonString'))]"
},
"booleanOutput": {
"type": "bool",
"value": "[json(parameters('jsonBoolean'))]"
},
"intOutput": {
"type": "int",
"value": "[json(parameters('jsonInt'))]"
},
"arrayOutput": {
"type": "array",
"value": "[json(parameters('jsonArray'))]"
},
"concatObjectOutput": {
"type": "object",
"value": "[json(concat('{\"a\": \"', parameters('concatValue'), '\"}'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
emptyObjectOutput | Boolean | True |
objectOutput | Object | {"a": "b"} |
stringOutput | String | test |
booleanOutput | Boolean | True |
intOutput | Integer | 3 |
arrayOutput | Array | [ 1, 2, 3 ] |
concatObjectOutput | Object | { "a": "demo value" } |
length
length(arg1)
Returns the number of elements in an array, characters in a string, or root-level properties in an object.
In Bicep, use the length function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
arg1 | Yes | array, string, or object | The array to use for getting the number of elements, the string to use for getting the number of characters, or the object to use for getting the number of root-level properties. |
Return value
An int.
Example
The following example shows how to use length
with an array and string:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"arrayToTest": {
"type": "array",
"defaultValue": [
"one",
"two",
"three"
]
},
"stringToTest": {
"type": "string",
"defaultValue": "One Two Three"
},
"objectToTest": {
"type": "object",
"defaultValue": {
"propA": "one",
"propB": "two",
"propC": "three",
"propD": {
"propD-1": "sub",
"propD-2": "sub"
}
}
}
},
"resources": [],
"outputs": {
"arrayLength": {
"type": "int",
"value": "[length(parameters('arrayToTest'))]"
},
"stringLength": {
"type": "int",
"value": "[length(parameters('stringToTest'))]"
},
"objectLength": {
"type": "int",
"value": "[length(parameters('objectToTest'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
arrayLength | Int | 3 |
stringLength | Int | 13 |
objectLength | Int | 4 |
null
null()
Returns null.
The null
function isn't available in Bicep. Use the null
keyword instead.
Parameters
The null function doesn't accept any parameters.
Return value
A value that is always null.
Example
The following example uses the null function.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"resources": [],
"outputs": {
"emptyOutput": {
"type": "bool",
"value": "[empty(null())]"
}
}
}
The output from the preceding example is:
Name | Type | Value |
---|---|---|
emptyOutput | Bool | True |
objectKeys
objectKeys(object)
Returns the keys from an object, where an object is a collection of key-value pairs.
In Bicep, use the objectKeys function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
object | Yes | object | The object, which is a collection of key-value pairs. |
Return value
An array.
Example
The following example shows how to use objectKeys
with an object:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"variables": {
"obj": {
"a": 1,
"b": 2
}
},
"resources": [],
"outputs": {
"keyArray": {
"type": "array",
"value": "[objectKeys(variables('obj'))]"
}
}
}
The output from the preceding example is:
Name | Type | Value |
---|---|---|
keyArray | Array | [ "a", "b" ] |
In JSON, an object is an unordered collection of zero or more key/value pairs. The ordering can be different depending on the implementations. For example, the Bicep items() function sorts the objects in the alphabetical order. In other places, the original ordering can be preserved. Because of this non-determinism, avoid making any assumptions about the ordering of object keys when writing code, which interacts with deployments parameters & outputs.
shallowMerge
shallowMerge(inputArray)
Combines an array of objects, where only the top-level objects are merged. This means that if the objects being merged contain nested objects, those nested object aren't deeply merged; instead, they're replaced entirely by the corresponding property from the merging object.
In Bicep, use the shallowMerge function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
inputArray | Yes | array | An array of objects. |
Return value
An object.
Example
The following example shows how to use shallowMerge
:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"variables": {
"firstArray": [
{
"one": "a"
},
{
"two": "b"
},
{
"two": "c"
}
],
"secondArray": [
{
"one": "a",
"nested": {
"a": 1,
"nested": {
"c": 3
}
}
},
{
"two": "b",
"nested": {
"b": 2
}
}
]
},
"resources": [],
"outputs": {
"firstOutput": {
"type": "object",
"value": "[shallowMerge(variables('firstArray'))]"
},
"secondOutput": {
"type": "object",
"value": "[shallowMerge(variables('secondArray'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
firstOutput | object | {"one":"a","two":"c"} |
secondOutput | object | {"one":"a","nested":{"b":2},"two":"b"} |
firstOutput shows the properties from the merging objects are combined into a new object. If there are conflicting properties (i.e., properties with the same name), the property from the last object being merged usually takes precedence.
secondOutput shows the shallow merge doesn't recursively merge these nested objects. Instead, the entire nested object is replaced by the corresponding property from the merging object.
union
union(arg1, arg2, arg3, ...)
Returns a single array or object with all elements from the parameters. For arrays, duplicate values are included once. For objects, duplicate property names are only included once.
In Bicep, use the union function.
Parameters
Parameter | Required | Type | Description |
---|---|---|---|
arg1 | Yes | array or object | The first value to use for joining elements. |
arg2 | Yes | array or object | The second value to use for joining elements. |
more arguments | No | array or object | More values to use for joining elements. |
Return value
An array or object.
Remarks
The union function uses the sequence of the parameters to determine the order and values of the result.
For arrays, the function iterates through each element in the first parameter and adds it to the result if it isn't already present. Then, it repeats the process for the second parameter and any additional parameters. If a value is already present, its earlier placement in the array is preserved.
For objects, property names and values from the first parameter are added to the result. For later parameters, any new names are added to the result. If a later parameter has a property with the same name, that value overwrites the existing value. The order of the properties isn't guaranteed.
The union function merges not only the top-level elements but also recursively merging any nested arrays and objects within them. See the second example in the following section.
Example
The following example shows how to use union
with arrays and objects:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"firstObject": {
"type": "object",
"defaultValue": {
"one": "a",
"two": "b",
"three": "c1"
}
},
"secondObject": {
"type": "object",
"defaultValue": {
"three": "c2",
"four": "d",
"five": "e"
}
},
"firstArray": {
"type": "array",
"defaultValue": [ "one", "two", "three" ]
},
"secondArray": {
"type": "array",
"defaultValue": [ "three", "four" ]
}
},
"resources": [
],
"outputs": {
"objectOutput": {
"type": "object",
"value": "[union(parameters('firstObject'), parameters('secondObject'))]"
},
"arrayOutput": {
"type": "array",
"value": "[union(parameters('firstArray'), parameters('secondArray'))]"
}
}
}
The output from the preceding example with the default values is:
Name | Type | Value |
---|---|---|
objectOutput | Object | {"one": "a", "two": "b", "three": "c2", "four": "d", "five": "e"} |
arrayOutput | Array | ["one", "two", "three", "four"] |
The following example shows the deep merge capability:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"variables": {
"firstObject": {
"property": {
"one": "a",
"two": "b",
"three": "c1"
},
"nestedArray": [
1,
2
]
},
"secondObject": {
"property": {
"three": "c2",
"four": "d",
"five": "e"
},
"nestedArray": [
3,
4
]
},
"firstArray": [
[
"one",
"two"
],
[
"three"
]
],
"secondArray": [
[
"three"
],
[
"four",
"two"
]
]
},
"resources": [],
"outputs": {
"objectOutput": {
"type": "Object",
"value": "[union(variables('firstObject'), variables('secondObject'))]"
},
"arrayOutput": {
"type": "Array",
"value": "[union(variables('firstArray'), variables('secondArray'))]"
}
}
}
The output from the preceding example is:
Name | Type | Value |
---|---|---|
objectOutput | Object | {"property":{"one":"a","two":"b","three":"c2","four":"d","five":"e"},"nestedArray":[3,4]} |
arrayOutput | Array | [["one","two"],["three"],["four","two"]] |
If nested arrays were merged, then the value of objectOutput.nestedArray would be [1, 2, 3, 4], and the value of arrayOutput would be [["one", "two", "three"], ["three", "four", "two"]].
Next steps
- For a description of the sections in an ARM template, see Understand the structure and syntax of ARM templates.
Maklum balas
https://aka.ms/ContentUserFeedback.
Akan datang: Sepanjang 2024, kami akan menghentikan secara berperingkat Isu GitHub sebagai kaedah maklum balas untuk kandungan dan menggantikannya dengan sistem maklum balas baharu. Untuk mendapatkan maklumat lanjut lihat:Kirim dan lihat maklum balas untuk