elsif

Elsih is a conditional control flow construct used in some programming languages to chain multiple conditions after an initial if. It stands for “else if” and is typically implemented as a distinct keyword or reserved word. When an if condition evaluates to true, the corresponding block executes and the rest of the chain is skipped. If false, the interpreter evaluates the next elsif condition, and if that is true, its block executes, and so on. If none of the conditions are true, an optional else block runs.

Languages: Ruby uses elsif as the keyword to introduce the next condition in the sequence. In Ruby, the syntax is: if condition1 then block1 elsif condition2 then block2 else block3 end. Perl also uses elsif in the same manner within a block started by if. In practice, “elsif” is a stylistic variant of “else if” common in languages influenced by Ruby or Perl. Other languages may use different spellings such as elseif or elif.

Usage considerations: elsif is used to test multiple mutually exclusive conditions in a clear, linear order. It is typically preferred over nested if statements for readability. However, long chains can become hard to read, and alternatives such as a case/when construct, polymorphism, or guard clauses may be more maintainable.

See also: if statement, else, case expression, elif, elseif.