Scala String: Creating String, Concatenation, String Length
1. Scala String – Objective
In this chapter, we will discuss Scala String in Detail. After this, you will be able to create a string in Scala. Moreover, we will learn how to create a format string and concatenate strings in Scala.
So, let’s start the Scala String Tutorial.
Stay updated with latest technology trends
Join DataFlair on Telegram!!
2. Introduction to Strings in Scala
An immutable object, a string in Scala is a sequence of characters. Once we declare it, we cannot modify it. The following is a Scala string:
3. Creating a Scala String
To define a string, we can use a ‘var’ or a ‘val’. When we use ‘var’, we can reassign to it. This isn’t the same with ‘val’:
scala> var word="rest" word: String = rest scala> word="reset" word: String = reset
By the way, reassigning ‘word’ to an Int will cause an error:
scala> word=7 <console>:12: error: type mismatch; found : Int(7) required: String word=7 ^
Now with ‘val’:
scala> val word="rest" word: String = rest scala> word="reset" <console>:12: error: reassignment to val word="reset"
We can also mention the data type if we don’t want to rely on type inference.
scala> var word:String="rest" word: String = rest scala> word="reset" word: String = reset
To make a lot of changes in your Scala string, you can use the StringBuilder class instead.
4. Find Length of a Scala String
An accessor method is one that’ll tell us about an object. One such method for strings is length(). It returns the number of characters a string holds. In the previous example,
scala> word.length() res0: Int = 5
Here are more than a couple more examples:
scala> "Ayushi".length() res1: Int = 6 scala> "".length() res2: Int = 0 scala> " ".length() res3: Int = 1
5. Concatenating Scala Strings
Concatenating two strings in Scala means joining the second to the end of the first. For this, we have the method concat() in the String class:
scala> "ab".concat("cde") res5: String = abcde
Let’s try using more than one:
scala> "Ayushi".concat(" ".concat("Sharma")) res6: String = Ayushi Sharma
We could also have done this using the + operator:
scala> "Ayushi"+" "+"Sharma" res7: String = Ayushi Sharma
6. Creating Format Strings in Scala
For the times we want to format numbers/values into our string, we can make use of one of the methods printf() and format(). Other than this, the class String has the method format() to return a String object instead of a PrintStream object.
scala> var (a:Int,b:Int,c:Int)=(7,8,9) a: Int = 7 b: Int = 8 c: Int = 9 scala> printf("a=%d, b=%d, c=%d",a,b,c)
a=7, b=8, c=9
For Integer data, we used %d. For Float and String data, we use %f and %s, respectively.
Hence, we studied how to create Scala String and creating format string in Scala. Along with this, we learned to concatenate and find a length of string. Still, have a confusion, feel free to ask in the comment session.