dowhile

Dowhile refers to the do-while loop, a control flow construct used in many imperative programming languages to repeat a block of code while a condition remains true. The key feature is that the loop body is executed at least once, because the condition is tested after the body.

Syntax is typically: do { ... } while (condition); In languages with C-like syntax, the trailing semicolon terminates the statement. The condition is evaluated after each iteration; if it is true, the loop repeats.

Supported languages include C, C++, Java, JavaScript, and PHP, which provide native do-while constructs. Perl also supports a do { ... } while form. Python does not have a native do-while loop, though similar behavior can be achieved with a while True loop and a break; Go has no native do-while, but can simulate the effect with a for loop. Some languages enforce specifics about braces and semicolons.

Common uses include menu-driven programs, input validation that must prompt at least once, and scenarios where the initial iteration must occur regardless of input. Example in a C-like syntax: do { printf("Enter a positive number: "); scanf("%d",&n); } while (n <= 0);

A do-while loop differs from a while loop in that the condition is tested after the first execution, guaranteeing at least one run of the loop body. Pitfalls include the risk of infinite loops if the condition never becomes false and insufficient changes to loop variables. Developers should ensure progress toward termination and consider language-specific nuances when using do-while.