MAKING DECISIONS
Most programs need to make decisions. There are several
statements available in the Pascal language for this. The IF
statement is one of the them. The RELATIONAL OPERATORS,
listed below, allow the programmer to test various variables
against other variables or values.
Symbol | Meaning |
= | Equal to |
> | Greater than |
< | Less than |
<> | Not equal to |
<= | Less than or equal to |
>= | Greater than or equal to |
The format for the IF THEN Pascal statement is,
if condition_is_true then execute_this_program_statement;
The condition (ie, A < 5 ) is evaluated to see if it's true. When the condition is true, the program statement will be executed. If the condition is not true, then the program statement following the keyword then will be ignored.
program IF_DEMO (input, output); {Program demonstrating IF THEN statement} 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!'); if number <> guess then writeln('Sorry, you guessed wrong.') end.