Scala – String Methods with Examples

In Scala, as in Java, a string is a sequence of characters. In Scala, objects of String are immutable which means a constant and cannot be changed once created. In the rest of this section, we discuss the important methods of java.lang.String class.

  1. char charAt(int index): This method is used to returns the character at the given index.

    Example:

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    // Scala program of charAt() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String]){
              
            // Getting a character at the given index
            // Using charAt() methods
            val result = "GeeksforGeeks".charAt(3)
            println("Result : " + result)
        }
    }

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    Output:

    Result : k
  2. int compareTo(Object o): This method is used for the comparison of one string to another object.
    Example:

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    // Scala program of compareTo() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String]){
              
            // Compare two strings
            // Using compateTo() methods
            val val1 = "Hello"
            val val2 = "GeeksforGeeks"
            val result = val1.compareTo(val2)
            println("Result : " + result)
        }
    }

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    Output:



    Result : 1
  3. int compareTo(String anotherString): This method is used to compares two strings lexicographically. If two strings match then it returns 0, else it returns the difference between the two.
    Example:

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    // Scala program of compareTo() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String]){
              
            // Compare two strings
            // Using compateTo() methods
            val result = "Geeks".compareTo("Geeks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : 0
  4. int compareToIgnoreCase(String str): This method is used for comparing two strings lexicographically. It ignoring the case differences.
    Example:

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    // Scala program of compareToIgnoreCase() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using compareToIgnoreCase() methods
            val result = "Geeks".compareToIgnoreCase("geeks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : 0
    
  5. String concat(String str): This method is used for concatenation of the two strings. It join two strings together and made a single string.Example:
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    // Scala program of concat() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String]){
              
            // Concatenate two strings
            // Using concat() methods
            val result = "Geeks".concat("forGeeks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : GeeksforGeeks
  6. Boolean contentEquals(StringBuffer sb): This method is used to compares a string to a StringBuffer’s contents. If they are equal then it returns true otherwise it will return false.
    Example:

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    // Scala program of contentEquals() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using contentEquals() methods
            val a = new StringBuffer("Geeks")
            val result = "Geeks".contentEquals(a)
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
  7. Boolean endsWith(String suffix): This method is used to return true if the string ends with the suffix specified. Otherwise, it returns false.
    Example:



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    // Scala program of endsWith() method   
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using endsWith() methods
            val result = "Geeks".endsWith("s")
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
  8. Boolean equals(Object anObject): This method is used to returns true if the string and the object are equal. Otherwise, it returns false.
    Example:

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    // Scala program of equals() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using equals() methods
            val result = "Geeks".equals("Geeks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
  9. Boolean equalsIgnoreCase(String anotherString): This methods works like equals() but it ignores the case differences.
    Example:

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    // Scala program of equalsIgnoreCase() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using equalsIgnoreCase() methods
            val result = "Geeks".equalsIgnoreCase("gEeks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
    
  10. byte getBytes(): This method helps in encoding a string into a sequence of bytes and it also helps in storing it into a new byte array.
    Example:

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    // Scala program of getBytes() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using getBytes() methods
            val result = "ABCcba".getBytes()
            println("Result : " + result)
        }
    }

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    Output:

    Result : [B@506e1b77
  11. int indexOf(int ch): This method helps in returning the index of the first occurrence of the character in the string.
    Example:

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    // Scala program of indexOf() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using indexOf() methods
            val result = "Geeks".indexOf('e')
            println("Result : " + result)
        }
    }

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    Output:

    Result : 1
  12. int indexOf(int ch, int fromIndex): This method works similar to that indexOf. The only difference is that it begins searching at the specified index.Example:
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    // Scala program of indexOf() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using indexOf() methods
            val result = "Geeksforgeeks".indexOf('g',5)
            println("Result : " + result)
        }
    }

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    Output:



    Result : 8
  13. int indexOf(String str): This method is used to return the index of the first occurrence of the substring we specify, in the string.
    Example:

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    // Scala program of indexOf() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using indexOf() methods
            val result = "Geeksforgeeeks".indexOf("ks")
            println("Result : " + result)
        }
    }

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    Output:

    Result : 3
  14. String intern(): This method is used to return the canonical representation for the string object.
    Example:

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    // Scala program of intern() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using intern() methods
            val result = "Geeks,\n\tForGeeks".intern()
            println("Result : " + result)
        }
    }

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    Output:

    Result : Geeks,
        ForGeeks
    
  15. int lastIndexOf(int ch): This method is used to return the index of the last occurrence of the character we specify.
    Example:

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    // Scala program of lastIndexOf() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using lastIndexOf() methods
            val result = "Geeks".lastIndexOf('e')
            println("Result : " + result)
        }
    }

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    Output:

    Result : 2
  16. int lastIndexOf(String str): This method is used to return the index of the last occurrence of the substring we specify, in the string.
    Example:

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    // Scala program of lastIndexOf() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using lastIndexOf() methods
            val result = "Geeksforgeeks".lastIndexOf("ek")
            println("Result : " + result)
        }
    }

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    Output:

    Result : 10
  17. int length(): This method is used to return the length of a string.
    Example:

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    // Scala program of length() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using length() methods
            val result = "Geeks".length()
            println("Result : " + result)
        }
    }

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    Output:



    Result : 5
  18. String replaceAll(String regex, String replacement): This method is used to replace the substring with the replacement string provided by user.
    Example:

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    // Scala program of replaceAll() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using replaceAll() methods
            val result = "potdotnothotokayslot".replaceAll(".ot","**")
            println("Result : " + result)
        }
    }

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    Output:

    Result : ********okays**
  19. String replaceFirst(String regex, String replacement): If in the above example, we want to replace only the first such occurrence.
    Example:

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    // Scala program of replaceFirst() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using replaceFirst() methods
            val result = "potdotnothotokayslot".replaceFirst(".ot","**")
            println("Result : " + result)
        }
    }

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    Output:

    Result : **dotnothotokayslot
  20. String[] split(String regex): This method is used to split the string around matches of the regular expression we specify. It returns a String array.
    Example:

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    // Scala program of split() 
    // method 
      
    // Creating object 
    object GfG 
      
        // Main method 
        def main(args:Array[String]) 
        
          
            // Applying split method 
            val result = "PfsoQmsoRcsoGfGkso".split(".so"
              
            for ( a <-result ) 
            
                // Displays output 
                println(a) 
            
              
        

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    Output:

    P
    Q
    R
    GfG
    
  21. Boolean startsWith(String prefix, int toffset): This method is used to return true if the string starts with the given index. Otherwise, it will return false.
    Example:

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    // Scala program of startsWith() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using startsWith() methods
            val result = "Geeks".startsWith("ee", 1)
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
  22. CharSequence subSequence(int beginIndex, int endIndex): This method is used to return the sub string from the given string. Here starting index and ending index of a sub string is given.
    Example:

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    // Scala program of subSequence() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using subSequence() methods
            val result = "Geeks".subSequence(1,4)
            println("Result : " + result)
        }
    }

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    Output:



    Result : eek
  23. String substring(int beginIndex): This method is used to return the characters of the string beginning from the given index till the end of the string.
    Example:

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    // Scala program of substring() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using substring() methods
            val result = "Geeks".substring(3)
            println("Result : " + result)
        }
    }

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    Output:

    Result : ks
  24. char[] toCharArray(): This method is used to convert the string into a CharArray.
    Example:

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    // Scala program of toCharArray() 
    // method 
      
    // Creating object 
    object GfG 
      
        // Main method 
        def main(args:Array[String]) 
        
          
            // Applying toCharArray method 
            val result = "GeeksforGeeks".toCharArray() 
              
            for(m1<-result) 
            
      
                // Displays output 
                println(m1
            
        

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    Output:

    G
    e
    e
    k
    s
    f
    o
    r
    G
    e
    e
    k
    s
  25. String toLowerCase(): This method is used to convert all the characters into lower case.
    Example:

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    // Scala program of toLowerCase() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using toLowerCase() methods
            val result = "GEekS".toLowerCase()
            println("Result : " + result)
        }
    }

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    Output:

    Result : geeks
  26. String toString(): This method is used to return a String object itself.
    Example:

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    // Scala program of toString() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using toString() methods
            val result = "9".toString()
            println("Result : " + result)
        }
    }

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    Output:

    Result : 9
  27. String toUpperCase(): This method is used to convert the string into upper case.
    Example:

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    // Scala program of toUpperCase() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using toUpperCase() methods
            val result = "Geeks".toUpperCase()
            println("Result : " + result)
        }
    }

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    Output:



    Result : GEEKS
  28. String trim(): This method is used to remove the leading and trailing whitespaces from the string.
    Example:

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    // Scala program of trim() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using trim() methods
            val result = " Geeks ".trim()
            println("Result : " + result)
        }
    }

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    Output:

    Result : Geeks
  29. String substring(int beginIndex, int endIndex): This method is used to return the part of the string beginning at beginIndex and ending at endIndex.
    Example:

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    // Scala program of substring() 
    // method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using substring() methods
            val result = "Piyush".substring(1, 4)
            println("Result : " + result)
        }
    }

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    Output:

    Result : iyu
  30. Boolean startsWith(String prefix): This method is used to return true if the string starts with the given prefix. Otherwise, returns false.
    Example:

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    // Scala program of startsWith() 
    // method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using startsWith() methods
            val result = "Ayush".startsWith(" Ay")
            println("Result : " + result)
        }
    }

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    Output:

    
    
  31. String[] split(String regex, int limit): This method is like split, the only change is that we can limit the number of members for the array.
    Example:

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    // Scala program of split() 
    // method 
      
    // Creating object 
    object GfG 
      
        // Main method 
        def main(args:Array[String]) 
        
          
            // Applying split method 
            val result = "NidhifsoSinghmsoAcso".split(".so", 2
          
            for ( m1 <-result ) 
            
                // Displays output 
                println(m1
            
      
        

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    Output:

    Nidhi
    SinghmsoAcso
  32. Boolean matches(String regex): This method is used to return true, if string matches the regular expression specified.
    Example:

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    // Scala program of matches() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using matches() methods
            val result = "Ayushi".matches(".i.*")
            println("Result : " + result)
        }
    }

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    Output:



    Result : false
  33. Boolean regionMatches(boolean ignoreCase, int toffset, String other, int offset, int len): This method is used to return true if two strings regions are equal.
    Example:

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    // Scala program of regionMatches() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using regionMatches() methods
            val result = "Ayushi".regionMatches(true, 0, "Ayush", 0, 3)
            println("Result : " + result)
        }
    }

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    Output:

    Result : true
  34. String replace(char oldChar, char newChar): This method is used to replace the oldChar occurences with the newChar ones.
    Example:

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    // Scala program of replace() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using replace() methods
            val result = "sanjay sharma".replace('s','$')
            println("Result : " + result)
        }
    }

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    Output:

    Result : $anjay $harma
  35. int hashCode(): This method is used to return hash code of a string.
    Example:

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    // Scala program of hashCode() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using hashCode() methods
            val result = "Ayushi".hashCode()
            println("Result : " + result)
        }
    }

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    Output:

    Result : 1976240247
  36. Boolean regionMatches(int toffset, String other, int offset, int len): This method does not have any ignore case, else it is same as above method.
    Example:

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    // Scala program of regionMatches() method 
      
    // Creating Object 
    object GFG
    {
          
        // Main method 
        def main(args: Array[String])
        {
              
            // Using regionMatches() methods
            val result = "Ayushi".regionMatches(true, 0, "Ayushi",
                                                0, 4)
            println("Result : " + result)
        }
    }

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    Output:

    Result : true



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