String interpolation

A string is a most commonly and heavily used class. String literal is also an instance of the string class. String interpolation has the most beautiful features in Kotlin.

Interpolation is basically smart string concatenation. A typical string concatenation can look as follows:

    val name="Kotlin Blueprints"
    println("Name $name")

In Android, there can be many cases where we do string concatenation and string interpolation can help us.

Remember! We have to display dynamic labels on TextView countless times in the app. The code for that using string interpolation can look as follows:

    txtFollowers.text = "$followersCount     
     ${getString(R.string.cnt_followers)}"
    txtFriendsCount.text = "$friendsCount   
     ${getString(R.string.cnt_friends)}"
    txtTweets.text = "${status.retweetCount}    
     ${getString(R.string.cnt_retweet)}"

If you observe the preceding code snippet, we actually use both objects and properties as well.

String interpolation internally uses the StringBuilder class to achieve this.  Also, we observed that there is no caching performed. Every time the statement executes a new object gets created. Let's hope that Kotlin will fix this soon in coming versions.