When we run program code, we deal with expressions and statements all the time. It's very important to understand the difference between these. Let's look at the following code:

1 + 1

This code is an expression because it contains variables, operators, and returns a single result. If a standalone element of program code represents an action, it is a statement:

println("Hello")

In the context of this section, the main point for us is that an expression returns something. In Kotlin, the try { ... } catch { ... } finally { ... } block is an expression and we can write something like this:

fun loadValue(): Int = throw Exception()

fun main(args: Array<String>) {
    println(try { loadValue() } catch (exception: Exception) { 4 })
}

Under the hood, this code works in the same way as if we were to write it in Java. To check this, you can decompile this code to Java:

public final class Example6Kt {
   public static final int loadValue() {
      throw (Throwable)(new Exception());
   }

   public static final void main(@NotNull String[] args) {
      Intrinsics.checkParameterIsNotNull(args, "args");

      int var1;
      try {
         var1 = loadValue();
      } catch (Exception var3) {
         var1 = 4;
      }

      System.out.println(var1);
   }
}

As you can see, there is no magic here. In contrast with Java, all control flow elements in Kotlin are expressions, which provides a more concise solution for common issues.