Table of Contents
- 1 What is reference in C++? Write the differences between reference and address of a variable?
- 2 What is the difference between typedef struct and struct in C++?
- 3 What is difference between typedef and macro in C?
- 4 What’s the difference between & and * in C++?
- 5 What is call by value call by reference in C language?
- 6 What is the difference between typedef and define in C?
- 7 What is the difference between a typedef-name and an optional attribute-specifier-seq?
What is reference in C++? Write the differences between reference and address of a variable?
Differences between pointers and references in C++ A pointer in C++ is a variable that holds the memory address of another variable. A reference is an alias for an already existing variable. Once a reference is initialized to a variable, it cannot be changed to refer to another variable.
What is the difference between typedef struct and struct in C++?
In C++, there is no difference between ‘struct’ and ‘typedef struct’ because, in C++, all struct/union/enum/class declarations act like they are implicitly typedef’ed, as long as the name is not hidden by another declaration with the same name.
What is a typedef in C++?
The typedef keyword allows the programmer to create new names for types such as int or, more commonly in C++, templated types–it literally stands for “type definition”. Typedefs can be used both to provide more clarity to your code and to make it easier to make changes to the underlying data types that you use.
Is there any difference in the #define and typedef in the following code?
typedef’s have the advantage that they obey scope rules, that is they can be declared local to a function or a block whereas #define’s always have a global effect.
What is difference between typedef and macro in C?
We can have symbolic names to datatypes using typedef but not to numbers etc. Whereas with a macro, we can represent 1 as ONE, 3.14 as PI and many more. We can have a type name and a variable name as same while using typedef. Compiler differentiates both.
What’s the difference between & and * in C++?
The & is a unary operator in C which returns the memory address of the passed operand. This is also known as address of operator. <> The * is a unary operator which returns the value of object pointed by a pointer variable.
What is typedef stackoverflow?
typedef is for defining something as a type. For instance: typedef struct { int a; int b; } THINGY; defines THINGY as the given struct.
Is typedef needed in C++?
typedef is necessary for many template metaprogramming tasks — whenever a class is treated as a “compile-time type function”, a typedef is used as a “compile-time type value” to obtain the resulting type.
What is call by value call by reference in C language?
The call by reference method of passing arguments to a function copies the address of an argument into the formal parameter. It means the changes made to the parameter affect the passed argument. To pass a value by reference, argument pointers are passed to the functions just like any other value.
What is the difference between typedef and define in C?
typedef vs #define. #define is a C-directive which is also used to define the aliases for various data types similar to typedef but with the following differences −. typedef is limited to giving symbolic names to types only where as #define can be used to define alias for values as well, q., you can define 1 as ONE etc.
Can a function have the same name as a typedef?
You can define a function with the same name of the struct as the identifiers are kept in different spaces, but you cannot define a function with the same name as a typedef as those identifiers collide. In C++, it is slightly different as the rules to locate a symbol have changed subtly.
How to give a name to a user defined data type?
You can use typedef to give a name to your user defined data types as well. For example, you can use typedef with structure to define a new data type and then use that data type to define structure variables directly as follows −
What is the difference between a typedef-name and an optional attribute-specifier-seq?
The identifier following the using keyword becomes a typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name. It has the same semantics as if it were introduced by the typedef specifier. In particular, it does not define a new type and it shall not appear in the type-id.