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:

Scala

// 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)
    }
}

1. Output:

Result : k

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : 1

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : 0

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : 0

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : GeeksforGeeks

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : true

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : true

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : true

1. Boolean equalsIgnoreCase(String anotherString): This methods works like equals() but it ignores the case differences.

Example:

Scala

// 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)
    }
}

1. Output:

Result : true

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : [B@506e1b77

1. int indexOf(int ch): This method helps in returning the index of the first occurrence of the character in the string. 

Example:

Scala

// 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)
    }
}

1. Output:

Result : 1

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : 8

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : 3

1. String intern(): This method is used to return the canonical representation for the string object.

Example:

Scala

// 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)
    }
}

1. Output:

Result : Geeks,
    ForGeeks

1. int lastIndexOf(int ch): This method is used to return the index of the last occurrence of the character we specify.

Example:

Scala

// 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)
    }
}

1. Output:

Result : 2

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : 10

1. int length(): This method is used to return the length of a string. 

Example:

Scala

// 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)
    }
}

1. Output:

Result : 5

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : ********okays**

1. String replaceFirst(String regex, String replacement): If in the above example, we want to replace only the first such occurrence.

Example:

Scala

// 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)
    }
}

1. Output:

Result : **dotnothotokayslot

1. 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:

Scala

// 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)
        }

    }
}

1. Output:

P
Q
R
GfG

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : true

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : eek

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : ks

1. char[] toCharArray(): This method is used to convert the string into a CharArray.

Example:

Scala

// 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)
        }
    }
}

1. Output:

G
e
e
k
s
f
o
r
G
e
e
k
s

1. String toLowerCase(): This method is used to convert all the characters into lower case.

Example:

Scala

// 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)
    }
}

1. Output:

Result : geeks

1. String toString(): This method is used to return a String object itself.

Example:

Scala

// 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)
    }
}

1. Output:

Result : 9

1. String toUpperCase(): This method is used to convert the string into upper case. 

Example:

Scala

// 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)
    }
}

1. Output:

Result : GEEKS

1. String trim(): This method is used to remove the leading and trailing whitespaces from the string.

Example:

Scala

// 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)
    }
}

1. Output:

Result : Geeks

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : iyu

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

Example:

Scala

// 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)
    }
}

1. Output:
2. 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:

Scala

// 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)
        }

    }
}

1. Output:

Nidhi
SinghmsoAcso

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

Example:

Scala

// 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)
    }
}

1. Output:

Result : false

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : true

1. String replace(char oldChar, char newChar): This method is used to replace the oldChar occurrences with the newChar ones. 

Example:

Scala

// 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)
    }
}

1. Output:

Result : $anjay $harma

1. int hashCode(): This method is used to return hash code of a string.

Example:

Scala

// 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)
    }
}

1. Output:

Result : 1976240247

1. 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:

Scala

// 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)
    }
}

1. Output:

Result : true