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While - repeat statements whilst a continuation condition is met

While Expression do Statement; Description The While keyword starts a control loop that is executed as long as the Expression is satisfied (returns True). The loop is not executed at all if the expression is false at the start. You need Begin or End markers if multiple statements are required in the loop. It is used when it is important that the statements are at only executed when necessary. Related commands Begin Keyword that starts a statement block Boolean Allows just True and False values Do Defines the start of some controlled action End Keyword that terminates statement blocks For Starts a loop that executes a finite number of times Repeat Repeat statements until a ternmination condition is met Until Ends a Repeat control loop Example code : Display integer squares until we reach 100 var num, sqrNum : Integer; begin num := 1; sqrNum := num * num; // Display squares of integers until we reach 100 in value While sqrNum <= 100 do begin // Show the square of num ShowMessage(IntToStr(num)+' squared = '+IntToStr(sqrNum)); // Increment the number Inc(num); // Square the number sqrNum := num * num; end; end; Show full unit code 1 squared = 1 2 squared = 4 3 squared = 9 4 squared = 16 5 squared = 25 6 squared = 36 7 squared = 49 8 squared = 64 9 squared = 81 10 squared = 100