Addition of functions and arguments in newly introduced Variables

Please add a functions and arguments in the variables as it will allow the user to reuse the functions and remove the repetitive tasks in variables. Please add it in a way that we can select the functions and apply on any prototype when using variables.
For example : if we want to increase or decrease the items in a cart, currently we have to apply separate variable and again select the variables and on 1 tap we want more than one variables to be changed so again we have to select the same variable, but if there was a function then we would have applied that function and change the arguments.