Do-while Loop in C++

September 17, 2025

Do while loop

On this page we will discuss about do while loop in C++ . Do while is a looping structure in C++, these types of loops are called Exit control or Post-test loops . In a do-while first the loop body is executed and then the test condition is checked  as a result one time execution of loop body is assured even if the condition is false for the first time

Do While Loop in C++ Language

  • Do while loop is very similar to the while loop. To do repetitive work control structure has been created.
  • In do while we execute some statements first and then check a condition.
  • That is why Do-while is known  as exit controlled loop. Which means that it will be implemented atleast once
  • If the condition is met we execute it again. We keep doing this until the condition keeps meeting.

Syntax:

do{
    // execute statement(s)
}while(condition(s));

Along with increment and initialization logic it may look like :

initialization;

do{
    // execute statement(s)
    incrementation;
    
}while(condition(s));

Loop Types in C++

Decision Making in C++

Array in C++

String in C++

Function in C++

Example 1:

Run 
#include<iostream>
using namespace std;
int main()
{
    int i = 1000; 
    // i is set as 1000 which is definitely greater than 5
    // the condition set below is (i <= 5) which will surely be never met
    // as the loop is incrementing (i++)
    // but still the loop is executed once anyways
    
    do{
        cout << i << ". Hello World\n";
        i++; 
    }
    while(i <= 5); 
    return 0;
}

Output:

1000. Hello World

Example 2:

Run

#include
using namespace std;
int main()
{
    int n = 25;
    int i = 1;
    do{
        cout << i << " ";
        i++; 
    }
    while(i <= n); 
    return 0;
}

Output:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Example 3:

Run 
#include<iostream>
using namespace std;
int main()
{
    int n = 100;
    int i = 1;
    do{
        // if divisible by 7 must leave 0 remainder
        // on applying modulo operator
        if(i % 7 == 0){
            cout << i << " ";
        }
        i++; 
    }
    while(i <= n); 
    return 0;
}

Output:

7 14 21 28 35 42 49 56 63 70 77 84 91 98

Example 4:

Run

#include 
using namespace std;
 
int main()
{
    char i='A';//inialisation
    do
    {
        cout << i << " : " << (int) i << " ";
        i++; // ascii codes are incremented
        
    } while(i<='Z'); // internally ascicodes are compared 
    return 0;
}

Output:

A : 65 B : 66 C : 67 D : 68 E : 69 F : 70 G : 71 H : 72 I : 73 J : 74 K : 75 L : 76 M : 77 N : 78 O : 79 P : 80 Q : 81 R : 82 S : 83 T : 84 U : 85 V : 86 W : 87 X : 88 Y : 89 Z : 90

Prime Course Trailer

Related Banners

Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription

Get Prime

Get over 200+ course One Subscription

Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others

Get Prime
Course List
Course List

Checkout list of all the video courses in PrepInsta Prime Subscription

Checkout list of all the video courses in PrepInsta Prime Subscription

Checkout
Checkout