Replacing characters in a String in Scala

Question

I am trying to create a method to convert characters within a String, specifically converting all '0' to ' '. This is the code that I am using:

def removeZeros(s: String) = {
    val charArray = s.toCharArray
    charArray.map( c => if(c == '0') ' ')
    new String(charArray)
}

Is there a simpler way to do it? This syntax is not valid:

def removeZeros(s: String) = 
  new String(s.toCharArray.map( c => if(c == '0') ' '))

Solution 1

You can map strings directly:

def removeZero(s: String) = s.map(c => if(c == '0') ' ' else c)

alternatively you could use replace:

s.replace('0', ' ')

Solution 2

Very simple:

scala> "FooN00b".filterNot(_ == '0')
res0: String = FooNb

To replace some characters with others:

scala> "FooN00b" map { case '0' => 'o'  case 'N' => 'D'  case c => c }
res1: String = FooDoob

To replace one character with some arbitrary number of characters:

scala> "FooN00b" flatMap { case '0' => "oOo"  case 'N' => ""  case c => s"$c" }
res2: String = FoooOooOob

Solution 3

According to Ignacio Alorre, if you want to replace others chars into string:

def replaceChars (str: String) = str.map(c => if (c == '0') ' ' else if (c =='T') '_' else if (c=='-') '_' else if(c=='Z') '.' else c)

val charReplaced = replaceChars("N000TZ")

Solution 4

The go-to way to do it is to use s.replace('0', ' ')

Just for training purposes you might use tail-recursion to achieve that as well.

def replace(s: String): String = {
  def go(chars: List[Char], acc: List[Char]): List[Char] = chars match {
    case Nil => acc.reverse
    case '0' :: xs => go(xs, ' ' :: acc)
    case x :: xs => go(xs, x :: acc)
  }

  go(s.toCharArray.toList, Nil).mkString
}

replace("01230123") // " 123 123"

and more generally:

def replace(s: String, find: Char, replacement: Char): String = {
  def go(chars: List[Char], acc: List[Char]): List[Char] = chars match {
    case Nil => acc.reverse
    case `find` :: xs => go(xs, replacement :: acc)
    case x :: xs => go(xs, x :: acc)
  }

  go(s.toCharArray.toList, Nil).mkString
}

replace("01230123", '0', ' ') // " 123 123"

Solution 5

/**
   how to replace a empty chachter in string
**/
val name="Jeeta"
val afterReplace=name.replace(""+'a',"")

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Comments

[Randall Schulz]

I understood the question to be literally removing the zeros. If you want to replace them with another single character, map works.

[Ignacio Alorre]

Do you know how to to replace double quote character? "

[Lee]

@IgnacioAlorre - Replace it with what? Something like s.replace('"', ' ') should work.