construct variable names dynamically in velocity - velocity

Question

I would like to know if it is possible to construct name of variable into velocity dynamically.
i.e. lets say I've 6 variables into velocity template [name1, name2, name3 .. name6] I would like to output them.
So I'm looking in something like:
#foreach ( $counter in [1..6] )
${name${counter}}
#end
is it possible somehow?

Answer 1

It is possible using the #evaluate directive:
#evaluate ('$name1')
#set ($d = '$')
#foreach ($i in [1..6])
#set ($varName = "${d}name${i}")
#evaluate($varName)
#end

Answer 2

You could construct a map and build the names of the keys to retrieve the values you want:
#set( $map = {"${name}1":'value1', "${name}2":'value2'} )
#foreach ( $counter in [1..6] )
#set( $key = "${name}$counter" )
$map.get(${key})
#end

Answer 3

Here is a trick to set velocity variable with dynamic name.
If you manage to tune velocity context beforehand in java code like this:
VelocityContext context = new VelocityContext(paramsMap);
context.put("all", paramsMap);
then it would be possible to define dynamic vars in template like this:
#set($dynamicDef = "varName=varValue")
#set($dynamicName = $dynamicDef.substring(0, $dynamicDef.indexOf('=')))
#set($dynamicValue = $dynamicDef.substring($dynamicDef.indexOf('=')).substring(1))
## create var with dynamic name
$all.put($dynamicName, $dynamicValue)
and use them later like this:
#if ($varName)
varName=$varName ## prints varName=varValue
#end