IF

Runs a block if a condition is true; or another block if it isn't.

Syntax

IF condition THEN BEGIN … END
IF condition THEN BEGIN … END ELSE BEGIN … END
IF condition THEN BEGIN … END ELSE IF condition THEN BEGIN … END ELSE BEGIN … END

THEN may be left out. ELSE may go at the start of the next line. As many ELSE IFs as are needed: the first block whose condition is true is run, else the ELSE block, if there is one.

Examples

IF L > W THEN BEGIN
    LINE P0, P2
END ELSE BEGIN
    LINE P1, P3
END

A diagonal one way when the box is wider than it is tall, the other when it isn't: change L or W and it is drawn again.

Notes

Compare with ==, != and ~= (nearly equal), not =: see Equal. To choose a value rather than a block, use ? : or SWITCH.

See also: Blocks and control flow.

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