UNTIL program instruction UNTIL program instruction Syntax UNTIL expression Function Indicate the end of a DO ... UNTIL control structure and specify the expression that is evaluated to determine when to exit the loop. The loop continues to be executed until the expression value is nonzero. Usage Considerations UNTIL must be used in conjunction with a DO control structure. See the description of the DO instruction for details. Parameter expression Real-valued expression, constant, or relation that is interpreted as either TRUE (nonzero) or FALSE (zero).
Details If the expression in the UNTIL statement is zero, program execution continues with the statement following the matching DO statement. If the expression is nonzero, program execution continues with the statement following the UNTIL statement. Example The following example is a loop that continues to prompt you to enter a number until you enter one that is greater than or equal to zero: DO PROMPT "Enter a positive number: ", number UNTIL number >= 0 Related Keyword DO program instruction EXIT program instruction NEXT program instruction WHILE program instruction eV+Language Reference Guide, v2.x, 18319-000 Rev A Page 555