%dw 2.0
import prependIfMissing from dw::core::Strings
output application/json
---
{
"a": prependIfMissing(null, ""),
"b": prependIfMissing("abc", ""),
"c": prependIfMissing("", "xyz"),
"d": prependIfMissing("abc", "xyz"),
"e": prependIfMissing("xyzabc", "xyz")
}
prependIfMissing
DataWeave 2.2 is compatible and bundled with Mule 4.2. Standard Support for Mule 4.2 ended on May 2, 2021, and this version of Mule will reach its End of Life on May 2, 2023, 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. |
prependIfMissing(String, String): String
Prepends the prefix
to the beginning of the string if the text
does not
already start with that prefix.
Introduced in DataWeave 2.2.0. Supported by Mule 4.2 and later.
Example
This example shows how prependIfMissing
behaves with different inputs and sizes.