What's the name of this programming feature?

Question

In some dynamic languages I have seen this kind of syntax:

myValue = if (this.IsValidObject)
{
    UpdateGraph();
    UpdateCount();
    this.Name;
}
else
{
    Debug.Log (Exceptions.UninitializedObject);
    3;
}

Basically being able to return the last statement in a branch as the return value for a variable, not necessarily only for method returns, but they could be achieved as well.

What's the name of this feature?

Can this also be achieved in staticly typed languages such as C#? I know C# has ternary operator, but I mean using if statements, switch statements as shown above.

Answer 1

It is called "conditional-branches-are-expressions" or "death to the statement/expression divide".

See Conditional If Expressions:

Many languages support if expressions, which are similar to if statements, but return a value as a result. Thus, they are true expressions (which evaluate to a value), not statements (which just perform an action).

That is, if (expr) { ... } is an expression (could possible be an expression or a statement depending upon context) in the language grammar just as ?: is an expression in languages like C, C# or Java.

This form is common in functional programming languages (which eschew side-effects) -- however, it is not "functional programming" per se and exists in other language that accept/allow a "functional like syntax" while still utilizing heavy side-effects and other paradigms (e.g. Ruby).

Some languages like Perl allow this behavior to be simulated. That is, $x = eval { if (true) { "hello world!" } else { "goodbye" } }; print $x will display "hello world!" because the eval expression evaluates to the last value evaluated inside even though the if grammar production itself is not an expression. ($x = if ... is a syntax error in Perl).

Happy coding.