whileclause

The term while clause can refer to two related concepts in language and computer science. In linguistics, it denotes a subordinate clause introduced by the conjunction while. In computer science, it names the loop construct that repeats a block of code while a condition holds. The two uses are distinct but share the idea of a condition governing subsequent content.

In grammar, a while clause often expresses time or a contrast between two situations. As a temporal clause, it indicates concurrent actions: while I was reading, the kettle boiled. As a contrastive clause, it marks a point of opposition: While I understand your point, I disagree. The typical structure is while + subject + finite verb. When the while clause precedes the main clause, a comma is common: While I was tired, I kept working. When the main clause comes first, the while clause usually does not require a comma: I kept working while I was tired. The phrase can also begin a participial form, such as While waiting, I checked my messages.

In programming, a while loop executes a block of statements repeatedly as long as a given condition remains true. Common syntax is while (condition) { statements }. The condition is tested before each iteration (a pretest loop). If the condition ever becomes false, execution continues after the loop. Many languages offer variations, such as do-while loops (post-test) and for loops with a condition component. Proper use avoids infinite loops and unintended side effects.

See also: subordinate clause, do-while loop, for loop, conditional sentence.