Differences Between The Inline Function And The Normal Function In C++

A function represents a set of code that can be reused to execute a specific operation. It is specified and invoked from various parts of the software. In C++, functions are categorized into various types depending on their purpose and characteristics. These include Standard functions, Inline functions, Recursive functions, Friend functions, Virtual functions, Lambda functions, and more. These functions play a crucial role in structuring and managing the codebase, ensuring the overall program's maintainability.

Normal function:

Standard functions are the most frequently used functions in C++. These functions are declared independently of any class and contain a distinct code block that is executed upon function call. Upon calling a standard function, the compiler generates a fresh stack frame to manage the function invocations.

This function specifies a return type, which dictates the type of value it will provide after performing calculations. Each time this function is invoked, it requires certain input values known as arguments. These arguments are processed by the function to produce a result. In contrast, certain functions do not have a return type, indicating that they have a void return type.

Syntax of the Normal Function:

It has the following syntax:

return_type function_name(parameters) {
 // Function code
 return result; 
}

The return type defines the data type of the value that the function yields. Parameters serve as the inputs for the function and are enclosed within parentheses. The function's logic is contained within curly braces {}. The return statement is employed to produce an output from the function when it is invoked.

Example:

Let's consider a C++ code example to demonstrate regular functions:

#include <iostream>
using namespace std;
int add(int a, int b) {
 return a + b;
};
int main() {
 int a,b;
 cout << "Enter the values of a and b "<< endl;
 cin >> a >> b;
 int result = add(a,b);
 cout << "Addition of two numbers are " << result << endl;
 return 0;
}

Output:

Inline function:

Inline functions in C++ are unique functions that consist of small, commonly used code snippets. These functions are incorporated directly into the code where they are invoked, hence referred to as inline functions. The compiler substitutes the function call with the specific code at the calling location to enhance performance optimization. As a result, no additional stack frame is generated for the function or redirection to a distinct code block, aiding in enhancing performance.

Syntax of the Inline function:

It has the following syntax:

inline return_type function_name(parameters) {
 // Function code
 return result; 
}

The term "inline" is employed to indicate the execution of the function inline. It is not obligatory to specify the return type, while the parameters represent the input values for the function.

Example:

Let's consider a C++ code example to demonstrate the usage of inline functions:

#include <iostream>
using namespace std;
inline int add(int a, int b) {
 return a + b;
};
int main() {
 int a,b;
 cout << "Enter the values of a and b "<< endl;
 cin >> a >> b;
 int result = add(a,b);
 cout << "Addition of two numbers are " << result << endl;
 return 0;
}

Output:

Similarities between the inline function and normal function:

There exist numerous resemblances between inline and regular functions. Some key similarities between inline and regular functions include:

Differences between the inline functions and normal functions:

There exist multiple distinctions between inline and regular functions. The primary variances between inline and regular functions can be outlined as follows: