the inline function used to write a line of code. the inline function starts with inline keyword. you can write a simple code in an inlined function. inline function is an important feature in c++.

When you called Function by Normal Method then the pointer will jump on the function location and the first function will be executed. after complete execution Functions pointer will come back in the main program.

And When You use an inline function then You where declare an inline function, the compiler will automatically paste code on that place. inline function works faster and saves time. the inline function makes a easy to program. when you write more logic in the inline function then the compiler will ignore it. you can create variables and write some code and compile and check it.

Also Read This :- call by value and call by reference in C++

Benefits

Reduce function calling overhead 

copy code resource in the program when you call the inline function 

Speed high and reduces time compare to normal function.

Limitation

compile can not perform when the below code available in the program

if the function contains any loop (like for loop, while loop, do while loop)

if the function has a static variable 

if the function is recursive

if the function return type is other than void 

if the function has a Switch statement and Go to statement

Example of Inline function in c++

#include<iostream>
using namespace std;

inline int square (int n)
{
   return n*n;
}

int main()
{
   int x;
   cout<<"Enter Your Number = "<<endl;
   cin>>x;

   cout<<"square of "<<x<<" = "<<square(x);
}

output

Enter Your Number = 2
square of 2 = 4