Arma Reforger:Scripting: Do's and Don'ts

⚠

Do follow Scripting Conventions.

Don't	Do
class ExampleClass { int LProcLgh; int stringlength( string Value ){ LProcLgh= Value.Length(); Print ( "String length obtained: "+LProcLgh ); return LProcLgh; } }	class ExampleClass { protected int m_iLastProcessedLength; int GetStringLength(string value) { m_iLastProcessedLength = value.Length(); Print("String length obtained: " + m_iLastProcessedLength); return m_iLastProcessedLength; } int GetLastProcessedLength() { return m_iLastProcessedLength; } }

⚠

Keep variables as close as possible to their usage.

Don't	Do
class ExampleClass { protected int m_iLength; int GetStringLength(string name) { m_iLength = name.Length(); Print("String length obtained: " + m_iLength); return m_iLength; } }	class ExampleClass { // keeping the variable into method scope and away from the instance int GetStringLength(string name) { int length = name.Length(); Print("String length obtained: " + length); return length; } }

⚠

Do not scope more than necessary.

Don't	Do
switch (value) { case 0: { Print("0"); break; } default: { Print("default"); break; } }	switch (value) { case 0: Print("0"); break; default: // brackets are needed only if variables are declared in the 'case' code { // otherwise scoping is superfluous (and very slightly impacts performance) string message = "default"; Print(message); break; } }

⚠

Keep a strong reference (ref keyword) to required objects.

Don't	Do
// this array only lists pointers but does not increase the reference count array<ExampleClass> classArray = new array<ExampleClass>(); for (int i = 0; i < 10; i++) { ExampleClass newInstance = new ExampleClass(); classArray.Insert(newInstance); // newInstance will be deleted at the end of the scope // as there are no references to it }	// this array keeps strong references to its items array<ref ExampleClass> classArray = new array<ref ExampleClass>(); for (int i = 0; i < 10; i++) { ExampleClass newInstance = new ExampleClass(); classArray.Insert(newInstance); // classArray keeps a strong reference to newInstance - it will not be cleared }

⚠

Avoid strong reference cyclic trap.

Don't

Do

ⓘ Here, both ParentClass and ChildClass have a strong reference to each other, keeping the reference count above zero - creating an "island of isolation" (see Arma Reforger:Scripting: Automatic Reference Counting for more information). class MainClass { ref SubClass m_SubClass; void MainClass() { m_SubClass = new SubClass(this); } } class SubClass { ref MainClass m_Parent; void SubClass(MainClass parent) { m_Parent = parent; } void DoSomething() { Print(m_Parent); } }

ⓘ Here, the MainClass needs the SubClass (it creates it in its constructor meaning it needs it to work) but the subClass does not require MainClass - if the MainClass reference doesn't exist, it will simply not use it. class MainClass { ref SubClass m_SubClass; void MainClass() { m_SubClass = new SubClass(this); } } class SubClass { MainClass m_Parent; // ref removed void SubClass(MainClass parent) { m_Parent = parent; } void DoSomething() { if (!m_Parent) // null safety check return; Print(m_Parent); } }