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isEmpty

DataWeave 2.1 is compatible with Mule 4.1. Standard Support for Mule 4.1 ended on November 2, 2020, and this version of Mule will reach its End of Life on November 2, 2022, when Extended Support ends.

Deployments of new applications to CloudHub that use this version of Mule are no longer allowed. Only in-place updates to applications are permitted.

MuleSoft recommends that you upgrade to the latest version of Mule 4 that is in Standard Support so that your applications run with the latest fixes and security enhancements.

isEmpty(Array<Any>): Boolean

Returns true if the given list (array) is empty, false if not.

Parameters

Name Description

elements

The list (an array) to evaluate.

Example

This example indicates whether the input array is empty.

Source

%dw 2.0
output application/json
---
{
  "empty" : isEmpty([]),
  "nonEmpty" : isEmpty([1])
}

Output

{
   "empty": true,
   "nonEmpty": false
}

isEmpty(String): Boolean

Returns true if the given string is empty, false if not.

Parameters

Name Description

value

A string to evaluate.

Example

This example indicates whether the input strings are empty.

Source

%dw 2.0
output application/json
---
{
  "empty" : isEmpty(""),
  "nonEmpty" : isEmpty("DataWeave")
}

Output

  {
    "empty": true,
    "nonEmpty": false
  }

isEmpty(Null): Boolean

Returns true if the input is null.

Parameters

Name Description

value

Null is the value in this case.

Example

This example indicates whether the input is null.

Source

%dw 2.0
output application/json
---
{
  "null" : isEmpty(null)
}

Output

{
  "null": true
}

isEmpty(Object): Boolean

Returns true if the given object is empty, false if not.

Parameters

Name Description

value

The object to evaluate.

Example

This example indicates whether the input object is empty.

Source

%dw 2.0
output application/json
---
{
  "empty" : isEmpty({}),
  "nonEmpty" : isEmpty({name: "DataWeave"})
}

Output

  {
    "empty": true,
    "nonEmpty": false
  }