Question

Difference between compile time errors, run time errors and loggical errors in computer c++

Answer 1

In one of my prof slides on ploymorphism, I see this piece of code with a couple of comments:
discountVariable = //will produce (DiscountSale)saleVariable;//run-time error discountVariable = saleVariable //will produce //compiler error
As you can see, it says in the first casting statement that it'll produce run-time error and in the other one it says it'll produce compiler error.


A run time error will only occur when the code is actually running. These are the most difficult - and lead to program crashes and bugs in your code which can be hard to track down.
An example might be trying to convert a string: "hello" into an integer:
string helloWorld = "hello"; int willThrowRuntimeError = Convert.ToInt32(helloWorld);
The compiler may not see this as a problem but when run an error will be thrown.
Compiler errors are due to inaccuracies in code, where the compiler throws an error to alert you to something which will not compile, and therefore cannot be run.
An example of a compiler error would be:
int = "this is not an int";
Hope that helps.