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Sizeof C++ Operator

C++ is a very convenient and easy language to learn as it’s a language that provides access to even minor and critical details. Wrapped up within these extraordinary features, we have a unique operator known as the “sizeoffunction. The sizeof c++ is one of the fundamental operators used for reference while programming.

The Sizeof Operator

The sizeof is an operator where the meaning is apparent from the name “sizeof” as it is used to evaluate the size of the:

The sizeof operator is a compile-time operator, which derives these data size(s) in bytes.

The syntax of sizeof is straightforward. It is as simple as:


Code The Fun Up

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Difficulty: Level 1

The Code Begins

#include <iostream>
using namespace std;

int main(){
    //Size of Primitive Data types
    cout<<"char: "<< sizeof(char)<<" bytes"<<endl;
    cout<<"int: "<< sizeof(int)<<" bytes"<<endl;
    cout<<"float: "<< sizeof(float)<<" bytes"<<endl;
    cout<<"double: "<< sizeof(double )<<" bytes"<<endl; 
    //Size of Data Types Modifiers
    cout<<"unsigned int: "<< sizeof(unsigned int)<<" bytes"<<endl;
    cout<<"short: "<< sizeof(short)<<" bytes"<<endl;
    cout<<"long: "<< sizeof(long)<<" bytes"<<endl;
    cout<<"long long: "<< sizeof(long long)<<" bytes"<<endl;
    cout<<"long double:  "<< sizeof(long double)<<" bytes"<<endl;

    //sizeof using variable names
    //Example 1 using integer
    cout<<"sizeof using variable names"<<endl;
    int a = 21;
    cout<<"a is "<< sizeof(a)<<" bytes"<<endl;
    //Example 2 using double
    double temp {22.24};
    cout<<"temp is "<< sizeof(temp)<<" bytes"<<endl;
    return 0;

CTFU: Explanation

In this sizeof program, we firstly included the primary header of C++, i.e., iostream, and used the fundamental namespace standard. After that, inside the main function, our actual code begins. Firstly we’ll begin by outputting the sizes of primitive data types, i.e., char, int, double, and double. Then we’ll print off the sizes of data types modifiers, i.e., unsigned int, short, long, long long, long double. After printing all the primitive data types and data type modifiers, we’ll move on to printing the sizes of variables that we’ll create.

So as you can see in Example 1, we’ve created an integer variable named “a” with a value of 21, and in the following line, we’ve printed its size for evaluation. Following Example 2, we’ve created another variable named “temp” with the value of 22.24 and, in the following line, we’ve again printed the size of “temp” to evaluate the size. If you saw it carefully, we’ve also added an end-line character (endl) at the end of every line, which allows you to separate the line reducing the clutter and the confusion in the output. And as the size is in bytes, we’ve added it to help you make more sense of the output.


So that’s all about the sizeof operator in the C++ hope you’ve understood it well and are following the latest C++ blogs. Besides hope, you loved our new format of CTFU (code the fun up), and you enjoyed coding while learning as it focuses on more practical knowledge than theoretical knowledge.

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