If Else

In all programming languages comparisons form the basis for flow control. Conditional statements are used to perform different actions based on different conditions.

In Miva Script we have the following conditional statements

• if expression: use this statement to execute some code only if a specified condition is true
• if...else statement: use this statement to execute some code if the condition is true and another code if the condition is false
• if...else if....else statement: use this statement to select one of many blocks of code to be executed

Attributes

• EXPR :  Required, returns a value interpreted as a conditional expression, typically involving a comparison, string, or logic operator. The expression must return a true for Miva Script to process the code that follows the <MvIF> tag. An <MvIF> tag must have a closing </MvIF> end tag.

Syntax

<MvIF EXPR = "{ condition }">
    Execute the code here if this condition is true, otherwise skip it.
</MvIF>

In this example the code executed branches based on the system clocks current hour of the day, where LT means Less Than. See Operators

<MvIF EXPR = "{ s.tm_hour LT 12 }">
    Good Morning.<br>
<MvELSE>
    Good Afternoon.<br>
</MvIF>

Multiple conditions can be used to determine which of several block s of code to execute.

<MvIF EXPR = "{ g.month LE 3 }">
    First Quarter.<br>

<MvELSEIF EXPR="{ g.month LE 6 }">
    Second Quarter.<br>

<MvELSEIF EXPR="{ g.month LE 9 }">
    Third Quarter.<br>

<MvELSE>
    Fourth Quarter.<br>

</MvIF>

Nested Conditionals

You can nest <MvIF> tags--that is, enclose one inside another. You must make sure that each <MvIF> tag has a corresponding </MvIF> end-tag. Indenting nested tags is not required but it makes your code more readable.

<MvIF EXPR="{age GE 17}">
    This person may be eligible to drive a motor vehicle.<br>
    <MvIF EXPR="{age GT 80}">
        This person requires a re-examination.<br>
    </MvIF>
    The license fee is $40.75.<br>
</MvIF>