PASCAL: AN INTRODUCTION

IF THEN ELSE
The IF statement can also include an ELSE statement, which specifies the statement (or block or group of statements) to be executed when the condition associated with the IF statement is false. Rewriting the previous program using an IF THEN ELSE statement,


	{ Program example demonstrating IF THEN ELSE statement }
	program IF_ELSE_DEMO (input, output);
	var     number, guess : integer;
	begin
	        number := 2;
	        writeln('Guess a number between 1 and 10');
	        readln( guess );
	        if number = guess  then
	           writeln('You guessed correctly. Good on you!')
	        else
	           writeln('Sorry, you guessed wrong.')
	end.

There are times when you want to execute more than one statement when a condition is true (or false for that matter). Pascal makes provison for this by allowing you to group blocks of code together by the use of the begin and end keywords. Consider the following portion of code,


        if number = guess  then
        begin
           writeln('You guessed correctly. Good on you!');
           writeln('It may have been a lucky guess though')
        end      {no semi-colon if followed by an else }
        else
        begin
           writeln('Sorry, you guessed wrong.');
           writeln('Better luck next time')
        end;     {semi-colon depends on next keyword }