Using Conditional Statement in SLD GeoServer

Question

Is there any way to use the conditional statement in SLD? somehow using if_then_else like this Pseudocode:

if (10 =< variable =< 100) {
    then Multiply variable by 2
} else {
    then Multiply it by 4
}

Or if it is also possible to have a multiple if_then_else

if (10 =< variable =< 100) {
    then Multiply variable by 2
} if (100 < variable =< 200) {
    then Multiply it by 3
} else {
    then Multiply it by 4
}

Example.sld

<ogc:Filter>
    <ogc:Function name="if_then_else">
        <ogc:PropertyName>variable</ogc:PropertyName>
        <!-- check if the "variable" is between 10 and 1000 -->
        <ogc:PropertyIsBetween>
            <ogc:LowerBoundary>
                <ogc:Literal>10</ogc:Literal>
            </ogc:LowerBoundary>
            <ogc:UpperBoundary>
                <ogc:Literal>100</ogc:Literal>
            </ogc:UpperBoundary>
        </ogc:PropertyIsBetween>

        <!-- if it is between this range then multiply it by 2 -->
        <ogc:Mul>
            <ogc:PropertyName>variable</ogc:PropertyName>
            <ogc:Literal>2</ogc:Literal>
        </ogc:Mul>

        <!-- else multiply it by 4 -->
        <ogc:Mul>
            <ogc:PropertyName>variable</ogc:PropertyName>
            <ogc:Literal>4</ogc:Literal>
        </ogc:Mul>
    </ogc:Function>
</ogc:Filter>

Answer 1

You can use something like this:

<ogc:Mul>
    <ogc:PropertyName>variable</ogc:PropertyName>
    <ogc:Function name="if_then_else">
        <ogc:Function name="between">
            <ogc:PropertyName>variable</ogc:PropertyName>
            <ogc:Literal>10</ogc:Literal>
            <ogc:Literal>100</ogc:Literal>
        </ogc:Function>
        <ogc:Literal>2</ogc:Literal>
        <ogc:Literal>4</ogc:Literal>
    </ogc:Function>
</ogc:Mul>

If you need more if statement you can change

<ogc:Literal>4</ogc:Literal>

with new if_then_else

More information about functions in sld expressions can be found on http://docs.geoserver.org/stable/en/user/filter/function_reference.html