Java is a hugely popular language, but it’s old. It has issues which everyone knows about but has to live with. That’s why Scala has been growing in popularity. It uses the JVM, and you can mix Java with Scala code.
While many things in the Scala language are familiar to Java programmers, there are also many differences, and it takes some effort to learn the language. The reward is worth the effort, though. Scala’s features allow code which is easier to maintain and has fewer bugs.
Scala provides better ways to do many things, but the workarounds which Java requires become habits. To gain the full benefits of the Scala language, a programmer needs to learn some new ways of thinking.
In Scala, everything is an object. Numbers are objects, avoiding the clumsiness of boxing. Booleans are objects. Even functions are objects.
Scala classes can’t have static members. This avoids mixing instance-based and static variables and functions. Instead, it allows creation of an object, which is a singleton class declared and instantiated in one step. A class can have a companion object of the same name to provide static functionality.
The Option container and the match expression are two of Scala’s most powerful features, but they give Java developers some trouble. An Option wraps an object or has the type None, which indicates no value. The match expression is like Java’s switch statement but more powerful; it can match classes and regular expressions as well as values. Together, they provide a better way to handle the absence of a value than Java’s null.
Java programmers spend much of their time making sure a NullPointerException can’t happen. Scala’s use of Option and match is a less error-prone way to check for a “no result” value. It’s necessary to unwrap an Option before using it, and the match expression makes it easy to check an Option’s type.
These two features, particularly in combination, take a while to understand, but they yield more solid code.
To keep up with new concepts in programming, developers have to learn new languages. The Scala language can be challenging at times, but it builds on familiar Java concepts and straightens out their inconsistencies. It’s a logical next step for Java programmers.