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.

isBlank(String | Null): Boolean

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


Name Description


A string to evaluate.


This example indicates whether the given values are blank. It also uses the not and ! operators to check that a value is not blank.


%dw 2.0
output  application/json
  "empty" : isBlank(""),
  "withSpaces" : isBlank("      "),
  "withText" : isBlank(" 1223"),
  // not blank
  "checkNotEmpty" : not isBlank(" 1234"),
  // ! for not in DataWeave 2.2.0 for Mule 4.2 and later
  "checkNotEmptyTwo" : ! isBlank(" 1234")


  "empty": true,
  "withSpaces": true,
  "withText": false,
  "checkNotEmpty": true,
  "checkNotEmptyTwo": true

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