Question

I have a function which takes a parameter and performs some calculations with it. The parameter is a number. However, when the parameter is 0, js treats it as undefined. So if I have a check for it like:

if (param == 0) { ... }

This is always false because param==0 is false but param==undefined is true.
So I have to rewrite the code and have a special case for when param=0.

Example:
result= param*123*456 +789;
This has to be changed to:

if (param == undefined) {
  result= 789;
} else {
  result= param*123*456 +789;
}
return result;

This is repeating code. There must be a better way. What is the better way?

Answer 1

You can perform a

param = param || 0;

at the top of your function.

This will make sure that if param is undefined it will become 0, so all your calculations will work as expected..