7.6 REPEAT Statement

The repeat statement repeats a statement until a condition, tested at the end of the loop, is met.

REPEAT statement UNTIL expr

The statement statement is executed. Then the condition expr is evaluated. If the condition is non-zero, then the loop terminates. Otherwise, the loop is repeated until the condition becomes non-zero. The statement statement is always executed at least once, even if the condition expr is true to begin with.