Function if

if condition trueResult [falseResult]

Returns one of two possible values, depending on the boolean value of the first argument.

Parameters:

condition - A boolean value or a block whose execution results in a boolean value.

trueResult - An object of any type.

falseResult - An object of any type.

Returns:

The evaluation of trueResult if condition evaluates to true, othwerise the evaluation of falseResult if it exists, or the null object if it is not specified.

The three argument version of the if function could be defined in terms of the cond function like this:

	define if ( aCondition truObj falseObj ) {
	    cond $aCondition $trueObj $falseObj
	}