Simple Conditional Statements (if-then-else)

The syntax is as follows, with the else clause being optional:

if <condition> then
    <statements>
[else
    <statements>]
end

The following example is used with display and input statements to capture end user feedback. This particular example evaluates the variable selected and sets the predefined action variable to FAIL:

if selected = "Cancel" then
    action = FAIL
end

The following example evaluates the variable orderTotal. If the order is greater than $5,000, the Boolean variable checkCredit is set to true:

if orderTotal > 5000 then
    checkCredit = true
end

We can go one step further with the previous example. We can also check whether the order is a credit order or a cash order by using the logical operator and to verify the two conditions. As before, the code checks if orderTotal is greater than $5,000 and now also requires that paymentType be set to "Credit":

if orderTotal > 5000 and paymentType = "Credit" then
    checkCredit = true
end

The final example shows the use of the or logical operator and the else clause. This example checks whether the variable lollipop is "cherry" or "raspberry". If so, eat is set to true. If not, eat is set to false:

if lollipop = "cherry" or lollipop = "raspberry" then
    eat = true
else
    eat = false
end

Some times you will need to handle more than two alternatives. To support this situation you can use the optional elseif clause:

if <condition> then
    <statements>
[elseif <condition> then
    <statements>]
...

[elseif <condition> then
    <statements>]
[else <condition> then
    <statements>]
end

In effect, each elseif concatenates two if-then-else statements. An arbitrary number of elseif blocks can be included, as well as a single optional else clause at the end. The example below uses the elseif clause and the else clause. This way, you can continue adding conditions indefinitely:

if selected = "Cancel" then
    action = FAIL
elseif selected = "Process" then
    orderStatus = "Reviewed"
    financeStatus = "Check"
else
    orderStatus = "In Review"
end