X++ Standards: if ... else and switch Statements
Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012
This topic describes X++ code style standards for the if...else statement and the switch statement.
if...else
If you have an if...else construction, then use positive logic:
Preferred:
if (true)
{
...
}
else
{
...
}
Avoid:
if (!false)
{
...
}
else
{
...
}
It is acceptable to use negative logic if throwing an error, and in cases where the use of positive logic would make the code difficult to understand.
There should be a space character between the if keyword and the open parenthesis.
Switch Statements
Always end a case with a break statement (or return/throw). If you intentionally want to make use of the fall-through mechanism supported in X++, replace the missing break statement with a comment line:
// Fall through
This comment line makes it visually clear to the reader that the fall-through mechanism is utilized.
Use 3 levels of indentation:
switch (Expression)
{
case: Constant:
Statement;
break;
...
}
Do not put parentheses around cases. .gif "Warning icon")
There should not be a space between the case keyword and the colon character.
Use a switch Instead of Nested if ... else Statements
Use switch statements instead of nested if...else statements.
Recommended:
switch (myEnum)
{
case ABC::A:
...
break;
case ABC::B:
...
break;
case ABC::C:
...
break;
default:
...
break;
}
Avoid:
if (myEnum == ABC::A)
{
...
}
else
{
if (myEnum == ABC::B)
{
...
}
else
{
if (myEnum == ABC::C)
{
...
}
else
{
...
}
}
}
See also
Comparison of if and switch Statements
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