JScript Conditional compilation

 

Conditional compilation can use new features of JScript and is compatible with older versions that do not support this feature.

Use the @ cc_on statement, @ if, or @ set statement to activate Conditional compilation. Some typical uses of Conditional compilation include the use of new features in JScript, embedded debugging support in the script, and trackingCode.

Conditional compilation code is usually put in comments, so the host that does not understand Conditional compilation (such as Netscape Navigator) ignores the Conditional compilation. The following is an example.

/* @ Cc_on @*/
/* @ If (@ _ jscript_version> = 4)
Alert ("jscript version 4 or better ");
@ Else @*/
Alert ("You need a more recent script engine .");
/* @ End @*/
This example uses a special annotation separator, which is used only when @ cc_on statements activate Conditional compilation. A script engine that does not support conditional compilation can only view information that requires updating the script engine.