eva/3 Application BuilderDeveloping eva/3 ApplicationsWorking with expressions 

Control structures

Control structures allows to modify the execution chain. As well, control functions can also be used.

Control structures have always a name and a body. The body will be specified with curly braces like { oder }.

Control structure Syntax
IF
Allows to branch the expression with a condition. Similar to this control structure the control function IIF can also be used.

Example: if(5>4) { ... }
IF( boolean Condition )
Condition: The condition which musst be fulfilled to execute the body.
ELSE
The else structure can be followed by an if and allows to specify the body which will be executed if the if condition results false.

Example: if(5<4) { ... } else { ... }
ELSE
WHILE
Loops the body so long since the loop condition returns true and aborts if the result is false.

Example: while($i<10) { $i++ }
WHILE( boolean Condition )
Condition: The condition which musst be fulfilled to execute the body.
FOR
Loops the body so long since the loop condition returns true and aborts if the result is false. Different to the WHILE loop, there is an initial and a counting parameter which can be specified.

Example: for($i<-0; $i<10; $i++) { ... }
FOR(variant Init; boolean Condition; variant Loop)
Init: This parameter is to be executed befor the loop starts.

Condition: The condition which musst be fulfilled to execute the body.

Loop: This parameter is always be executed if the loop body is entered (but not the first time).