trying to use my custom class constructor without new [closed] - c++

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coming from java i would like to not have to deal with de-allocation when creating new custom or other library's objects.
today i was trying to create an instance of my entity object like:
entity cube = new entity("entityName")
because this is how entity's constructor is formatted
but i get the following error:
cannot convert from |entity *| to |entity|
i noticed there are no errors if i just remove the new keyword, and i was wondering two things.
what does the error while using new mean ? (i'm pretty confident with how pointers work but not completely as i started with java.)
is it ok for me to create objects like that without the new keyword or is an object even created? (because there are no errors.)

Answer 1

new entity("entityName")
means "create an instance of entity in the free store and return a pointer to that instance".
Since a pointer to an entity is not the same as an entity, you cannot initialise an entity with that value unless you have yet another constructor.
The way to do what you want is
entity cube("entityname");
And you need a good book on C++.

Answer 2

First, I suggest you to read a C++ tutorial. It has much more complexity than Java.
This is a very partial Java to C++ "how to convert" guide that I can give you:
Java code:
void sayHello(String name) {
system.out.println("Hello, " + name);
}
public static void main(String args[]) {
String name = "James"; // <-- This string is of course created in the dynamic memory
sayHello(name); // <-- "name" will be passed by reference to the "sayHello()" method
}
Equivalent in C++ - option 1:
void sayHello(const std::string &name) {
std::cout << "Hello, " << name << std::endl;
}
int main() {
std::string name("James"); // <-- Variable is created on the stack
sayHello(name); // <-- Although "name" is not a pointer, it will be passed by reference to "sayHello", as "name" is defiend there with "&", which means that it is a reference
}
A reference is a very "weird" type - it behaves like a local variable, although it actually points to an instance that does not have to be on the stack of the current function or on the stack at all.
C++ - option 2:
void sayHello(const std::string *name) {
std::cout << "Hello, " << *name << std::endl; // <-- dereferenceing "name" using a preceding star, as "cout" needs the variable itself and not its address
}
int main() {
std::string *name = new std::string("James"); // <-- Instance is created in the dynamic memory
sayHello(name); // <-- Sending the pointer "name" to the "sayHello" function
// You will need to free "name" somewhere in the code unless you don't care about memory leaks
}
There are more options, like passing the instance by value (not recommended in such case), or like creating it in the dynamic memory and deref

Answer 3

what does the error while using new mean ? (i'm pretty confident with how pointers work but not completely as i started with java.)
No. C++ is different about this, you don't use an allocation (new) to initialize cube:
entity cube("entityName");
is it ok for me to create objects like that without the new keyword or is an object even created? (because there are no errors.)
No. See above. ("because there are no errors." I doubt this, there should at least be compiler warnings if you assign entity from a pointer.)