Javascript returning SUM 0

Sorry for this basic JS question.

I have this code:

let myResult = 0

        if (value0 > (value1 * value2)) {
          myResult = (value1 * value2) * value3;
        } else {
          myResult = valueExtra * value3;
        }
        return ( myResult )

my value is always 0.

I know it’s because let is not changing, but I don’t know why.

Could you help me, please?