Revision as of 03:57, 20 December 2011

Exception Handling (Error Runtime Handling)

An exception is an error occurs in the runtime (the excution) of program. The CGScript language uses the try/catch statement and the throw expression to implement the exception handling.

Syntax

try-catch statement

try {
   // codes that could throw an exception
}
catch (exception) {
   // codes that execute when exception is thrown in the try block
}

In the try clause, when a line of code cause the exception/error, the exception will be thrown to the catch clause and the codes in catch clause will process that exception. All codes below the code which cause the exception/error will be ignored.
The exception can be any type (E.g. exception object, number, string...)
CGScript language does not support multi catch clauses.

throw expression

throw [expression]

The expression can be any type (E.g. exception object, number, string...)
If throw is used in catch clause, it will be re-throw. See below examples for information about re-throw.

Examples

@@ Line 12: / Line 12: @@
 }
 catch (exception) {
-    // codes that execute when exception-declaration is thrown in the try block
+    // codes that execute when exception is thrown in the try block
 }
 </pre>
+* In the try clause, when a line of code cause the exception/error, the exception will be thrown to the catch clause and the codes in catch clause will process that exception. All codes below the code which cause the exception/error will be ignored.
 * The '''exception''' can be any type (E.g. exception object, number, string...)
 * CGScript language does not support multi catch clauses.