GeeksforGeeks

Directly accessing Grandparent’s member in Java: Predict the output of following Java program.

Default parameters for templates in C++: Like function default arguments, templates can also have default arguments. For example, in the following program, the second parameter U has the default value as char.

In C++, if a derived class redefines base class member method then all the base class methods with sane name become hidden in derived class.

Consider the following prototype of free() function which is used to free memory allocated using malloc() or calloc() or realloc().

Spaghetti stack A spaghetti stack is an N-ary tree data structure in which child nodes have pointers to the parent nodes (but not vice-versa)

Space Complexity: The term Space Complexity is misused for Auxiliary Space at many places.

Consider the following algorithm for building a Heap of an input array A.

Interpolation search works better than Binary Search for a sorted and uniformly distributed array.

Following two algorithms are generally taught for Minimum Spanning Tree (MST) problem.

In C, fseek() should be preferred over rewind().

Access specifiers for classes or interfaces in Java: In Java, methods and data members of a class/interface can have one of the following four access specifiers. The access specifiers are listed according to their restrictiveness order.

Initialization of static variables in C: In C, static variables can only be initialized using constant literals. For example, following program fails in compilation.

Static blocks in Java Unlike C++, Java supports a special block, called static block (also called static clause) which can be used for static initializations of a class.

Result of comma operator as l-value: Using result of comma operator as l-value is not valid in C. But in C++, result of comma operator can be used as l-value if the right operand of the comma operator is l-value.

In C++, this pointer is passed as a hidden argument to all non-static member function calls. The type of this depends upon function declaration. If the member function of a class X is declared const, the type of this is const X* (see code 1 below),

In C++, a structure is same as class except the following differences:

In C++ and Java, functions can not be overloaded if they differ only in the return type.

The order of operands of logical operators &&, || are important in C/C++.

In Java, all methods in an interface are public even if we do not specify public with method names. Also, data fields are public static final even if we do not mention it with fields names. Therefore, data fields must be initialized.

ASCII NUL, ASCII 0 (’0′) and Numeric literal 0.

Endian order and binary files While working with binary files, how do you measure their endianness?

Critical Section: In simple terms a critical section is group of instructions/statements or region of code that need to be executed atomically (read this post for atomicity), such as accessing a resource (file, input or output port, global data, etc.).

In Java, it is compiler error to give more restrictive access to a derived class function which overrides a base class function.

In C, the only operation that can be applied to struct variables is assignment. Any other operation (e.g. equality check) is not allowed on struct variables.

In Java, constructor of base class with no argument gets automatically called in derived class constructor. For example, output of following program is: