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C++ Inline Functions

C++ Inline Functions

In this tutorial, we will learn about inline functions in C++ and how to use them with the help of examples.

In C++, we can declare a function as inline. This copies the function to the location of the function call in compile-time and may make the program execution faster.

Before following this tutorial, be sure to visit the C++ Functions.

Inline Functions

To create an inline function, we use the inline keyword. For example,

inline returnType functionName(parameters) {
    // code

Notice the use of keyword inline before the function definition.

C++ Inline Function

#include <iostream>
using namespace std;

inline void displayNum(int num) {
    cout << num << endl;

int main() {
    // first function call

    // second function call

    // third function call

    return 0;



Here is how this program works:

Working of inline functions in C++
Working of inline functions in C++

Here, we created an inline function named displayNum() that takes a single integer as a parameter.

We then called the function 3 times in the main() function with different arguments. Each time displayNum() is called, the compiler copies the code of the function to that call location.