spot | Tiny file search utility | Command Line Interface library

This should work:

Digging in Google I found:

You can add HTML using

You must make a distinction between the static type of a variable (the type known at compile time) and the run time type of an object reference assigned to a variable.

The static type of p is Parent in both cases because it is declared as Parent p. No matter what you assign it. You may even assign it null.

The run time type of the value of p after the assignment is Child in the first case and Parent in the second case. It would be undetermined if p was null.

It is okay to assign a Child to a Parent, because the Child class derives from Parent. A Child is therefore a Parent (in OO terms).

However, a Parent is not a Child, because it does not derive from it. Therefore, in the second case, you cannot cast p to Child. In the first case the cast is valid, because you cast the object to its actual run time type. It tells the compiler, I know that this object assigned to a Parent variable is a Child, so, please, treat it as a Child. This does not involve any conversion; however, a runtime check will be performed, possibly throwing an exception, if the cast was not allowed.

You were asked to explain it from point of view of stack and heap memory. I'm sorry to say, but this has absolutely nothing to do with stack or heap memory. It has to do with inheritance rules and assignment compatibility.

Of course, here we are dealing with reference types (classes). This allows us to derive Child from Parent. This would not be possible with value types (structs). The point is reference type versus value type, not heap versus stack, which is an implementation detail. And btw., a value type (struct) field in a class will also be stored on the heap.

See also: The Stack Is An Implementation Detail, Part One and Two (Eric Lippert's blog)

You did not ask for it but casting to a derived type is mostly preceded by a type test, because you usually do not know the run time type in advance. Let us say that the Child class adds a new method DriveParentsToDespair() (only children can do this). Then you could use Type testing with pattern matching to test the type and assign it to a new variable at the same time:

It seems what you want this:

When comparing strings, you should always use the equals method, i.e. string1.equals(string2);.

Weird stuff can happen when you use the equality operator.

I am facing the same same issue using the JS SDK and on API version 10.0.

There is currently an outage / issue from facebooks side. You can see the details of the issue "JS SDK and Social Plugins Failure" here and the Bug report here.

The first place you should check for the status of APIs and SDKs is the "Facebook Platform Status" page which has identified this issue 6 hours ago.

Here is an infographic to show when a collision message will be detected by OnCollisionEnter between two objects. Both objects will need some sort of collider, and will most likely need a Rigidbody.

You will not want to set isTrigger as that will not make it physically react to a collision, but will just detect when a collision occurs. It will also not call OnCollisionEnter but will call OnTriggerEnter. Setting both not as triggers, adding a collider, and giving them Rigidbodies should allow the collision to be detected. You will also need to attach this script to one of the objects that have the collider. Are there other components on the objects you are using?

A . before a string in a selector indicates a class. So .class will select an element with the class of class.

A # before a string in a selector indicates an ID. So #foo will select an element with the ID of foo.

So

Here's what I believe you are after.

A couple of changes:

1. Your while loops can contain the validation that you are wanting to perform as their condition. If your validation becomes more complex then you can consider moving back to a boolean to break the while loop, but it feels overly complex for your requirements.

2. Removal of the if statements. The whole idea of a dictionary is that you can specific a key and get a value, so having an elif for every potential key is overly cumbersome. Just concatenate the validated user input to derive the key.