Often you will require to put brackets around some statements to ensure that they are reevaluated, particularly arguments in printf statements.
Answer to your direct question:
If a variable is not initialized,
awk uses default values: --
numeric = 0 (zero) : -- string = " " (null string)
Code:
print(1 2) = 3
print(1 2 "") = 12
Normally: to force numeric evaluation add 0, to force string evaluation add ""
