The American Programmer

How do you say equal, not equal, greater than, less than in REXX?

REXX IF

Comparison operators

=	Equal.  If numeric, when compared algebraically.  (1.0 is equal to 001.000.)  If not numeric, when padded with leading or trailing spaces.  ("Sue" is equal to "   Sue   ".)  Case is significant: "SUE" is not equal to "sue".

<>	Not equal, the negation of "=".  Algebraic comparison and padding are performed.

><	Not equal, the negation of "=".  Algebraic comparison and padding are performed.

\=	Not equal, the negation of "=".  Algebraic comparison and padding are performed.

¬=	Not equal, the negation of "=".  (The symbol "¬" may not be found on all keyboards.)  Algebraic comparison and padding are performed.

^=	Not equal, the negation of "=".  (The symbol "^" may not be found on all keyboards.)  Algebraic comparison and padding are performed.

>	Greater than.  Algebraic comparison and padding are performed.

<	Less than.  Algebraic comparison and padding are performed.

>=	Greater than or equal to.  Algebraic comparison and padding are performed.

¬<	Not less than.  (The symbol "¬" may not be found on all keyboards.)  Algebraic comparison and padding are performed.

\<	Not less than.  Algebraic comparison and padding are performed.

<=	Less than or equal to.  Algebraic comparison and padding are performed.

¬>	Not greater than.  (The symbol "¬" may not be found on all keyboards.)  Algebraic comparison and padding are performed.

\>	Not greater than.  Algebraic comparison and padding are performed.
==	Strictly equal on a character-by-character basis.  No algebraic comparison or padding is done.
	
¬==	Strictly not equal, the negation of "==".  (The symbol "¬" may not be found on all keyboards.)  No algebraic comparison or padding is done.

\==	Strictly not equal, the negation of "==".  No algebraic comparison or padding is done.

>>	Strictly greater than.  No algebraic comparison or padding is done.

>>=	Strictly greater than or equal to.  No algebraic comparison or padding is done.

<<	Strictly less than.  No algebraic comparison or padding is done.

<<=	Strictly less than or equal to.  No algebraic comparison or padding is done.

¬>>	Strictly not greater than.  (The symbol "¬" may not be found on all keyboards.)  No algebraic comparison or padding is done.

¬<<	Strictly not less than.  (The symbol "¬" may not be found on all keyboards.)  No algebraic comparison or padding is done.

&	And.  The conditions on both sides of this operator must be true. 

|	Or.  One or both of the conditions on either side of this operator must be true. 

&&	Exclusive Or.  Only one, but not both, of the conditions on either side of this operator must be true. 




The difference between = and ==

= Equal
= asks if two things are equal, accounting for leading/trailing spaces and numeric equivalency.

IF "JOE" = "JOE    " THEN SAY "YES" /* they are equal */
IF 100   = 0100.00   THEN SAY "YES" /* they are equal */

== Strictly Equal
== asks if two things are exactly equal, on a character by character basis
IF "JOE" == "JOE    " THEN SAY "YES" /* they are not equal */
IF 100   == 0100.00   THEN SAY "YES" /* they are not equal */

IF "JOE" == "JOE" THEN SAY "YES" /* they are equal */
IF 100   == 100   THEN SAY "YES" /* they are equal */

The same principle applies to ¬==, \==, >>,  >>=, <<, <<=.

|  Home |  Programming |  Books for Computer Professionals |  Privacy |  Terms |  Contact |
|  Site Map and Site Search |  Programming Manuals and Tutorials |  The REXX Files | Top of Page |