XploRe Help : if

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Group:	Flow Control
See also:	else endif

Function:		if
Description:		if does conditional branching, if the first element of the argument is true. If has to be followed by an endif. Else is an optional part of if sequences.

Usage:	`if (cond) <xplore commands> {else <xplore commands>} endif`
Input:
	`cond`	n-dimensional array of condition

Note:

Even if the condition is a multidimensional array only the first element is checked for TRUE (!=0) or FALSE (==0). You have to realize the difference between "if (x=6)" and "if (x==6)": "if (x=6)" means that x is assigned the value 6, but in the case of "if (x==6)" x is compared with 6. The following examples show the differences in practice.

Example:

proc(y)=abso(x) if(x<0) y=-1.0*x else y=x endif endp abso(-eh)

Result:

Contents of y

[1,]   2.7183

Example:

proc(y)=null(x) if(x=0) y=1 else y=0 endif endp null(eh)

Result:

Syntax Error
in null line: 3
Parse Error
on position 6 in line 3