Layout Rules & Indentation in Dynamics 365 Finance & Operations
Question 38 — Formatting X++ for readability: indentation, statements per line, spacing and braces.
Interview Question
Model Answer (Short)
A good layout uses formatting to emphasise the structure of the code and make it easy to read. Use the
default Code Editor settings (Smart Indent, 4-character indent, save tabs as spaces). Write
one statement per line and one declaration per line. Methods start with a single
tab and their body with two tabs. There is no space between a method name and its parentheses;
one or two parameters can go on the same line, but more than two should each go on a new indented
line. Put one space after if, switch, for and
while, and use curly braces around all code blocks — even single-statement blocks —
except around the case labels of a switch.
Indentation & Editor Settings
Indentation rules
- Always indent code correctly — proper indentation reflects structure.
- Use the default Code Editor settings: Smart Indent, 4-character indent, save tabs as spaces.
- Methods start with a single tab; everything inside a method starts with two tabs.
- If subsequent lines aren't auto-indented, indent them by one tab stop (four spaces).
Statements & parameters
- Write only one statement per line.
- Write only one declaration per line.
- No space between the method name and the opening parenthesis.
- One or two parameters may share a line; more than two go each on a new line, indented four spaces.
- Put a blank line between processing units.
Spacing & braces
- Put one space after the opening keyword of
if,switch,for,while. - Use curly braces around all code blocks — except around the
caselabels of a switch. - Use curly braces even if the block has only one statement.
Prerequisites (Rule 5)
- Visual Studio with the Dynamics 365 developer tools.
- A custom model / package for your objects.
- Editor configured with Smart Indent, 4-char indent, tabs as spaces.
Code Example — Correct layout & braces
public void processOrders()
{
SalesTable salesTable; // one declaration per line
while select salesTable
{
// Always use braces, even for one statement
if (salesTable.SalesStatus == SalesStatus::Backorder)
{
this.process(salesTable);
}
}
}Parameter formatting (more than two)
// One or two params can share a line
public Amount calc(Qty _qty, Price _price)
{
return _qty * _price;
}
// More than two params -> each on its own indented line
public Amount calcDiscounted(
Qty _qty,
Price _price,
Percent _discount,
CustAccount _custAccount)
{
return (_qty * _price) * (1 - _discount / 100);
}Avoid: poor indentation & missing braces
// BAD: no braces, poor indentation, multiple statements per line
if (myCondition)
doSomething(); doSomethingElse();
// GOOD
if (myCondition)
{
doSomething();
doSomethingElse();
}Points the interviewer wants to hear
- Use default editor settings: Smart Indent, 4-char, tabs as spaces.
- One statement and one declaration per line.
- No space before method parentheses; split >2 params onto new lines.
- One space after
if/switch/for/while. - Braces around all blocks, even single statements (except switch cases).
Likely Follow-up Questions
- Why use braces even for a single-statement block?
- How should you format a method with more than two parameters?
- What are the recommended default editor indentation settings?
- Where are curly braces intentionally omitted?
Key Takeaway
Consistent layout makes X++ readable: use 4-space Smart Indent, one statement per line, no space before method parentheses, split long parameter lists, add a space after control keywords, and always use curly braces (except around switch cases).