Control Flow

The following keywords are used for controlling the execution flow in the APL programming language.

Keyword	Description	Example
break	Terminates the execution of the current loop.	while(i++ < 10) { if( i == 5 ) { break; } }
continue	Terminates execution of the current iteration of the loop, and continues execution of the next iteration.	while( i++ < 10) { if( i%2 == 0 //your code { else { continue; } } }
for	`for` loop (for-each loop): The `for` loop is used to iterate through a list's elements in a first-to-last order. This type of loop only consists of a variable declaration and a list type. The declared variable, which is only available in the scope of the `for` loop, is assigned an element in each iteration. `for` loop (advanced): Creates a loop that consists of three expressions. The first expression performs the initialization of a variable used for counting iterations. A variable declared in this expression is only available in the scope of the for loop. The second expression contains a condition that must evaluate to true or false. The loop iterates until the condition evaluates to false. The third expression is evaluated at the end of each loop iteration, before the next evaluation of the condition. This is typically used to update or increment the counting variable in the condition.	list<int> listOfInts = listCreate(int,1,2,3); for (int i: listOfInts) { //your code } list<string> listOfStrings = listCreate(string,"1","2","3"); for (string s: listOfStrings) { //your code } for( int i=0; i<10; i++ ) { //your code }
if else	Used to execute code with conditions.	if (myVar == "ABC") {// do_this} else {// do_that}
return	Stops the execution of the current function block.	if ( ANumber == null ) { return;}
while	Loops while a condition is true. Note! If the APL code generates an infinity loop it can be stopped by, in the Workflow Monitor or Execution Manager, selecting the Stop button and Stop Immediate. This will however not wor if the loop is running in the `initialize` or `deinitialize` blocks.	while( i < 20 ) { // do_stuff}
switch case	Allows an expression to be tested for equality against a list of values or types, where each of these is a case. The cases are evaluated against the variable in order, from top to bottom. After a match, the remaining cases will not be evaluated. Testing values: The value for a `case` must be the same data type as in the switch expression. Testing types: The type for a `case` must be followed by a variable declaration as shown in the example column. A switch statement can have an optional default case, `else`, which must appear at the end of the `switch`. The default case can be used for performing a task when the variable does not match any of the other cases.	//Testing values switch (str) { case "one" { debug("One"); } case "two" { debug("Two"); } else debug("other"); } //Testing types switch (input) { case (PulseUDR p){ debug(p.Sequence); } case (MyUDR m) { debug(m.aField); } } //Testing container types  switch (value) {  case (map<any, any> m) {  debug("This is a map.");   }  case (list<any> l){  debug("This is a list.");  }  }