PASCAL: AN INTRODUCTION

LOOPS
The most common loop in Pascal is the FOR loop. The statement inside the for block is executed a number of times depending on the control condition. The format's for the FOR command is,

	FOR var_name := initial_value TO final_value DO  program_statement;


	FOR var_name := initial_value TO final_value DO
	begin
	    program_statement; {to execute more than one statement in a for }
	    program_statement; {loop, you group them using the begin and    }
	    program_statement  {end statements                              }
	end;                   {semi-colon here depends upon next keyword   }


	FOR var_name := initial_value DOWNTO final_value DO  program_statement;

You must not change the value of the control variable (var_name) inside the loop. The following program illustrates the for statement.


	program  CELCIUS_TABLE ( output );
	var      celcius : integer; farenhiet : real;
	begin
	         writeln('Degree''s Celcius   Degree''s Farenhiet');
	         for  celcius := 1  to  20  do
	         begin
	             farenhiet := ( 9 / 5 ) * celcius + 32;
	             writeln( celcius:8, '      ',farenhiet:16:2 )
	         end
	end.

CLASS EXERCISE
What is the resultant output when this program is run.


	program  FOR_TEST ( output );
	var      s, j, k, i, l : integer;
	begin
	         s := 0;
	         for  j:= 1 to 5 do
	         begin
	             write( j );
	             s := s + j
	         end;
	         writeln( s );
	         for  k := 0 to 1 do write( k );
	         for  i := 10 downto 1 do writeln( i );
	         j := 3; k := 8; l := 2;
	         for  i := j to k do  writeln( i + l )
	end.

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PROGRAM NINE
For the first twenty values of farenhiet, print out the equivalent degree in celcuis (Use a tabular format, with appropiate headings). [C = ( 5 / 9 ) * Farenhiet - 32]

Use the statement writeln('<14>'); to clear the screen.

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