Environment variables manipulation - jenkins

Question

When using:
echo "${env.PRODUCT_NAME}"
it will echo:
MyProdName
When using:
echo "${env.MyProdName_Key}"
it will echo:
123456789
I would like to use something as follows:
echo "${env.${env.PRODUCT_NAME}_Key}"
Is this possible? How?

Answer 1

In Bash this is termed as variable in direction
Try using variables to make it further simplified
PRODUCT_NAME=$(echo "${env.PRODUCT_NAME}")
This would assign PRODUCT_NAME=MyProdName
Similarly
MyProdName=$(echo "${env.MyProdName_Key}")
This would assign MyProdName=123456789
Now when you print PRODUCT_NAME value you will get
echo ${PRODUCT_NAME}
MyProdName
And adding '!' variable indirection will give you the value of another variable values
echo ${!PRODUCT_NAME}
123456789

Answer 2

Maybe this will help you somehow:
def env = [
PRODUCT_NAME:'MyProdName',
MyProdName_Key: 123456789,
]
println "${env[env.PRODUCT_NAME+'_Key']}"
env is Map in the example provided but it works in the exactly same way.

Answer 3

Important note, regardless of how you're deriving variables:
There's no need to use string interpolation if the only value in a
string is a variable itself. This just clutters your code.
Instead of:
echo "${env.PRODUCT_NAME}"
you can do:
echo.PRODUCT_NAME.
Additionally you can grab nested object values dynamically using bracket notation
def obj = [a: '1']
echo obj[a] // outputs '1'
Using these put together, you can do:
def prodName = env.PRODUCT_NAME //will set var prodName to "MyProdName"
echo env[prodName + '_Key'] //gets nested field with key "MyProdName_Key"
(Note: this is similar to Opal's answer, hopefully my breakdown helps)