CreateUiDefinition collection functions

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These functions can be used with collections, like JSON strings, arrays and objects.

contains

Returns true if a string contains the specified substring, an array contains the specified value, or an object contains the specified key.

Example: string contains

The following example returns true:

"[contains('webapp', 'web')]"

Example: array contains

Assume element1 returns [1, 2, 3]. The following example returns false:

"[contains(steps('demoStep').element1, 4)]"

Example: object contains

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns true:

"[contains(steps('demoStep').element1, 'key1')]"

empty

Returns true if the string, array, or object is null or empty.

Example: string empty

The following example returns true:

"[empty('')]"

Example: array empty

Assume element1 returns [1, 2, 3]. The following example returns false:

"[empty(steps('demoStep').element1)]"

Example: object empty

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns false:

"[empty(steps('demoStep').element1)]"

Example: null and undefined

Assume element1 is null or undefined. The following example returns true:

"[empty(steps('demoStep').element1)]"

filter

Returns a new array after applying the filtering logic provided as a lambda function. The first parameter is the array to use for filtering. The second parameter is the lambda function that specifies the filtering logic.

The following sample returns the array [ { "name": "abc" } ].

"[filter(parse('[{\"name\":\"abc\"},{\"name\":\"xyz\"}]'), (item) => contains(item.name, 'abc'))]"

first

Returns the first character of the specified string; first value of the specified array; or the first key and value of the specified object.

Example: string first

The following example returns "c":

"[first('contoso')]"

Example: array first

Assume element1 returns [1, 2, 3]. The following example returns 1:

"[first(steps('demoStep').element1)]"

Example: object first

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns {"key1": "Linux"}:

"[first(steps('demoStep').element1)]"

last

Returns the last character of the specified string, the last value of the specified array, or the last key and value of the specified object.

Example: string last

The following example returns "o":

"[last('contoso')]"

Example: array last

Assume element1 returns [1, 2, 3]. The following example returns 3:

"[last(steps('demoStep').element1)]"

Example: object last

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns {"key2": "Windows"}:

"[last(steps('demoStep').element1)]"

length

Returns the number of characters in a string, the number of values in an array, or the number of keys in an object.

Example: string length

The following example returns 7:

"[length('Contoso')]"

Example: array length

Assume element1 returns [1, 2, 3]. The following example returns 3:

"[length(steps('demoStep').element1)]"

Example: object length

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns 2:

"[length(steps('demoStep').element1)]"

map

Returns a new array after calling a lambda function on a provided array. The first parameter is the array to use for the lambda function. The second parameter is the lambda function.

The following sample returns a new array with every value doubled. The result is [2, 4, 6].

"[map(parse('[1, 2, 3]'), (item) => mul(2, item))]"

The following sample returns a new array ["abc", "xyz"].

"[map(parse('[{\"name\":\"abc\"},{\"name\":\"xyz\"}]'), (item) => item.name)]"

skip

Bypasses a specified number of elements in a collection, and then returns the remaining elements.

Example: string skip

The following example returns "app":

"[skip('webapp', 3)]"

Example: array skip

Assume element1 returns [1, 2, 3]. The following example returns [3]:

"[skip(steps('demoStep').element1, 2)]"

Example: object skip

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns {"key2": "Windows"}:

"[skip(steps('demoStep').element1, 1)]"

split

Returns an array of strings containing the substrings of the input delimited by the separator.

The following sample returns the array [ "555", "867", "5309" ].

"[split('555-867-5309', '-')]"

take

Returns a specified number of contiguous characters from the start of the string, a specified number of contiguous values from the start of the array, or a specified number of contiguous keys and values from the start of the object.

Example: string take

The following example returns "web":

"[take('webapp', 3)]"

Example: array take

Assume element1 returns [1, 2, 3]. The following example returns [1, 2]:

"[take(steps('demoStep').element1, 2)]"

Example: object take

Assume element1 returns:

{
  "key1": "Linux",
  "key2": "Windows"
}

The following example returns {"key1": "Linux"}:

"[take(steps('demoStep').element1, 1)]"

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