Scala String Methods

Scala String equals() Method Example

You can also use equal() method to compare two string objects. It returns true if both string object are equal otherwise returns false.

class StringExample{
    var s1 = "Scala string example"
    var s2 = "Hello Scala"
    var s3 = "Hello Scala"
    def show(){
        println(s1.equals(s2))
        println(s2.equals(s3))
    }
}

object MainObject{
    def main(args:Array[String]){
        var s = new StringExample()
        s.show()
    }
}

Output:

false
true

Scala compareTo() Method Example

The compareTo() method compares the given string with current string lexicographically. It returns positive number, negative number or 0.

If first string is greater than second string, it returns positive number (difference of character value). If first string is less than second string, it returns negative number and if first string is equal to second string, it returns 0.

s1 > s2 => positive number  
s1 < s2 => negative number  
s1 == s2 => 0  

class StringExample{
    var s1 = "Scala string example"
    var s2 = "Hello Scala"
    var s3 = "Hello Scala"
    def show(){
        println(s1.compareTo(s2))
        println(s2.compareTo(s3))
    }
}

object MainObject{
    def main(args:Array[String]){
        var s = new StringExample()
        s.show()
    }
}

Output:

11
0

Scala Concatenation Example by using + (Plus) Operator

In scala, you can concatenate string by using + operator. An example is given below in which two strings are concatenated by using + operator.

class StringExample{
    var s1 = "This is "+"Scala string example"
    def show(){
        println(s1)
    }
}

object MainObject{
    def main(args:Array[String]){
        var s = new StringExample()
        s.show()
    }
}

Output:

This is Scala string example

Scala String concat() Method Example

Apart from + operator, you can also use concat() method to concatenate two strings. It is a predefined method of string class.

class StringExample{
    var s1 = "This is "
    var s2 = "Scala string example"
    def show(){
        println(s1.concat(s2))
    }
}

object MainObject{
    def main(args:Array[String]){
        var s = new StringExample()
        s.show()
    }
}

Output:

This is Scala string example

Scala substring() Method Example

The substring() method is used to get substring from a string. By specifying start and end index as argument you can get substring according to your requirement. It is a predefined method of string class.

class StringExample3{
    var s1 = "Scala string example"
    def show(){
        println(s1.substring(0,5))
    }  
}

object MainObject{
    def main(args:Array[String]){
        var s = new StringExample3()
        s.show()
    }
}

Output: