You declare variables explicitly in script via the Dim statement, the Public statement, & the Private statement. For illustration:

Dim DegreesFahrenheit

You declare multiple variables through separating each variable name along with a comma. For illustration:

Dim Top, Bottom, Left, Right

You can also declare a variable implicitly through using its name in your script simply. Generally that is not a good practice since you could misspell the variable name in one or more places, causing unexpected results while your script is running. For that purpose, the Option Explicit statement is obtainable to require explicit declaration of all variables.