When an operand evaluates to NONE
The following table explains how an operator expression evaluates when an operand evaluates to none.
The symbol A represents one operand of the expression and B
represents the other operand. The symbol != means not equal to
.
| Operator Expression | Condition | Evaluates to: |
|---|---|---|
| A / B | A = NONE B = NONE | NONE |
| A*B | A = NONE B = NONE | NONE |
| A / B | A != NONE B = NONE | 0 |
| A*B | A != NONE B = NONE | 0 |
| A + B | A = NONE B = NONE | NONE |
| A - B | A = NONE B = NONE | NONE |
| A + B | A = NONE B != NONE | B |
| A - B | A = NONE B != NONE | -B |
| A + B | A != NONE B = NONE | A |
| A - B | A != NONE B = NONE | A |
| A > B | A = NONE B = NONE | FALSE |
| A < B | A = NONE B = NONE | FALSE |
| A = B | A = NONE B = NONE | TRUE |
| A > B | A = NONE B != NONE | FALSE |
| A < B | A = NONE B != NONE | TRUE |
| A = B | A = NONE B != NONE | FALSE |
| A > B | A != NONE B = NONE | TRUE |
| A < B | A != NONE B = NONE | FALSE |
| A = B | A != NONE B = NONE | FALSE |
For example, in this operator expression:
Total = #Guests + 1
if #Guests evaluates to "none", the value for Total will be 1.