The join function joins an array based on the key with a delimiter and last_delimiter.

Syntax

output = join(expression,key,delimiter,last_delimiter)

Inputs

expression : a reference to a variable or any [[expression|Expressions]]. This variable needs to be a json array or a string array

key : This is optional. It represents the key if the expression is a json array. Skip this parameter in case of String array.

delimiter : The delimiter to join on.

last_delimiter : The last delimiter.

Output

output : The joined string.

Example flow

Schema dependentsSchema {
    spouse {
       string name
    }
    children[
       string name
    ]
}

Schema joinOutputSchema {
    string dependentsText
}

value dependents -> dependentsSchema {
    spouse { "Foo" }
    children [
       { "A" }
       { "B" }
       { "C" }
    ]
}

Mapping finalMapping input dependents output joinOutputSchema {
    joinOutputSchema.dependentsText = join(dependents.children,name,",","and")
}

Output for Example Flow

{
   "dependentsText" : "A, B and C"
}