The IF operator evaluates one or more conditions and creates a new branch of code.

Low-level IF statements

00d6: if <N> <condition 1> <condition 2> ... <condition N+1> 004D: jump_if_false <label>

N means the total number of conditions within the IF statement and the way the evaluation of conditions happens.

<label>- a name of the label where script jumps if the IF statement is false. <condition> - any conditional opcode evaluating to true or false

If you have the Conditions check enabled in the options, you can replace the if number with the keywords AND or OR. The compiler calculates the correct value itself.

if and 
    $var > 0
    $var2 == 10.0
jf @anywhere

The compiler writes the number 1 instead of and.

IF AND - conditions connected with the logical operator AND (a replacement for if 1..7) IF OR - conditions connected with the logical operator OR (a replacement for if 21..27)

High-level Constructs

To make writing conditions easier there are high-level constructs that don't require any additional labels:

IF <N>/AND/OR <condition 1> <condition 2> ... <condition N+1> THEN <commands if the statement is true> END

IF <N>/AND/OR <condition 1> <condition 2> ... <condition N+1> THEN <commands if the statement is true> ELSE <commands if the statement is false> END

A condition is created by the rules described for low-level conditions. After THEN you have to specify the command(-s) that are executed if the condition is met. After ELSE you have to specify the command(-s) that are executed if the condition is not met.

The IF statement is closed with the word END.

if $var == 5
then
    Inc($var)
else
    Dec($var)
end

Relational Operators

• a == b - a is equal to b

• a >= b - a is greater than or equal to b

• a > b - a is greater than b

• a < b - a is less than b

• a <= b - a is less than or equal to b

• a <> b - a is not equal to b

a and b are operands. The compiler is able to figure out an opcode if one of the operands is a number or a string literal, or both variable' type is known.