Create an String dynamically based on parameters-CodePudding

I'm parametrizing a query in Scala.

I have an array of strings with column names named colNames.

I want to create an string where for each name of the string the output is A.colName = B.colName and then join all the items in the array putting an " AND " string between each item.

Example of input

val colNames = Array("colName1","colName2")
val table1 = "A"
val table2 = "B"

Example of the desired output

"A.colName1 = B.colName1 AND A.colName2 = B.colName2"

In a non FP language I would do that with a for loop, but I don't know how to do it in Scala in a functional way.

CodePudding user response：

You can use the map and mkString methods on Array:

scala> colNames map { colName => s"${table1}.${colName} = ${table2}.${colName}" } mkString " AND "
val res0: String = A.colName1 = B.colName1 AND A.colName2 = B.colName2