Zero Initialization in C++

Zero initialization is setting the initial value of an object in c++ to zero.

Syntax

T{} ; char array [n] = “”;

The situations in which zero initialization are performed are −

• Named variable with static or thread-local storage is initialized to zero.

• It is used as initialization of values for non-class types and members of a class that do not have a constructor.

• It is used to initialize a character array when its length is greater than the number of characters that are to be assigned.

Points to remember

• Some types of variables like static variables and thread-local variables are first initialized to zero then reinitialized to a value when called.

• A zero-initialized pointer is called a null pointer.

Example

Program to show the implementation of zero initialization in C++ −

 Live Demo

#include <iostream> #include <string> using namespace std; struct zeroInitialization {    int x, y, z; }; float f[3]; int* p; string s; int main(int argc, char* argv[]){    zeroInitialization obj = zeroInitialization();    cout<<"Zero initialized object variable :\t";    cout<<obj.x<<"\t"<<obj.y<<"\t"<<obj.z<<"\n";    cout<<"Zero initialized float value :\t";    cout<<f[0]<<"\t"<<f[1]<<"\t"<<f[2]<<"\n";    cout<<"Zero initialized pointer value :\t";    cout<<p<<"\n";    return 0; }

Output

Zero initialized object variable : 0 0 0 Zero initialized float value : 0 0 0 Zero initialized pointer value : 0