thenbranch

Thenbranch is the portion of a conditional statement that is executed when the evaluated condition is true. It represents the "positive" outcome in a decision flow and is paired with an else-branch, which handles the alternate path when the condition is false. The term is descriptive rather than a formal keyword in many languages, but it helps describe the structure of conditional constructs across families of programming languages.

Syntax varies. Some languages explicitly label the block with then, such as Pascal and Ada: if condition then begin ... end;. In languages without an explicit then, the language still defines a true-branch that runs when the condition holds, typically enclosed by braces or indentation (for example, C, Java, Python).

Single-line conditionals sometimes use a compact form where the thenbranch corresponds to the expression executed if the condition is true, followed by an else-expression. The thenbranch can be a single statement or a block of statements, and it may be nested within other conditional constructs to implement complex decision logic.

Beyond programming, the concept appears in formal logic as the consequent of implication (if p then q) and in decision modeling as the path taken when a predicate is satisfied. Terminology varies by domain; some sources refer to the "true branch" or "positive branch" instead of thenbranch. Understanding the thenbranch aids in reading and constructing conditional statements, control flow, and decision trees.