[discrete]
[[esql-replace]]
=== `REPLACE`
The function substitutes in the string (1st argument) any match of the regular expression (2nd argument) with the replacement string (3rd argument).

If any of the arguments are `NULL`, the result is `NULL`.

. This example replaces an occurrence of the word "World" with the word "Universe":

[source.merge.styled,esql]
----
include::{esql-specs}/docs.csv-spec[tag=replaceString]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/docs.csv-spec[tag=replaceString-result]
|===