Replacing variable values using newly dated version of the variable [duplicate]

This question already has an answer here:

• Replacing NAs with latest non-NA value 15 answers

I am trying to replace update values for x, q, z using the recently available version of the variable indexed by date. In STATA, we can easily do it as a for loop. How can I do the same using purrr dynamically?

STATA

• y refers to the date value of 20191125

local y 20191125

foreach v in x, q, z{
replace `v'=`v'`y' if !missing(`v'`y')
}

Data

+----+----+---+-----------+-----------+-----------+
| X  | Q  | Z | X20191125 | Q20191125 | Z20191125 |
+----+----+---+-----------+-----------+-----------+
| 1  | 2  | 3 |         6 |         8 |         0 |
| 1  | NA | 0 |         1 |         1 |         1 |
| NA | 0  | 1 |         5 |         4 |         2 |
+----+----+---+-----------+-----------+-----------+