Reduce function is used to do any computation while iterating on an array, so the computation result is not lost during iteration.
This function is useful for grouping together items in an array based on some value that is generated from each item in the array.
This function is useful for when you need to remove duplicate items from an Array.
Iterates over items in an array and outputs the results into a new array.
This function can be applied to an array. It iterates the array and matches the values with the expression. The output of the filter function is an array with the matching values.
DataWeave 2.0 makes it easier to define an array with a range (" to ").
For functions that DataWeave provides, you can represent the first, second, and third arguments of the passed lambda as $, $$, and $$$, respectively. When you do this, you do not need to specify the arguments of the lambda when you pass it to the function.
This type of notation is referred to as infix since the operator is in between the two operands that it is working on.
In other words, lambdas become useful when you want to pass functions as arguments to other functions, or return a function from a function.
DataWeave provides multiple ways to create functions. Just like we have named functions, we have functions without names, called lambdas.