CODEWITHSUNDEEP
stringscala
locorecto
locorecto

Reputation: 1203

Replace multiple words on string using Map of replacements

I have a map of replacements

val replacements = Map( "aaa" -> "d", "bbb" -> "x", "ccc" -> "mx")

I would like to replace all occurrences of each map key in the string with the corresponding value.

val str = "This aaa is very bbb and I would love to cccc"
val result = cleanString(str, replacements)
result = "This d is very x and I would love to mx"

I have done 

val sb = new StringBuilder(str)
for(repl <- replacements.keySet) yield {
  sb.replaceAllLiterally(repl, replacement.get(repl))
}

but I would like something more functional like a map or fold where the function I apply to the string returns another string without needing a mutable variable that is modified inside the loop.

Upvotes: 8

Views: 7390

Answers (3)

Kicey
Kicey

Reputation: 63

You can use regex to do that. Be careful about the order.

val str = "aaaaaa"
val relaceMap = Map("aaaaa" -> "C", "a" -> "A", "aaa" -> "B")
val pattern = relaceMap.keys.mkString("|").r
val result = pattern.replaceAllIn(str, m => relaceMap(m.matched)) // CA

Upvotes: 0

mfirry
mfirry

Reputation: 3692

I don't really like this, but it should work:

str.split(" ").toList.map { s => 
  if(replacements.get(s).isDefined) { 
    replacements(s) 
  } else { 
    s  
  } 
}.mkString(" ")

Upvotes: 0

akuiper
akuiper

Reputation: 214927

One option: use foldLeft on the Map with str as the initial parameter:

replacements.foldLeft(str)((a, b) => a.replaceAllLiterally(b._1, b._2))
// res8: String = This d is very x and I would love to mxc

Upvotes: 27

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