Loops are handy because they save time, reduce errors, and they make code more readable.

C++ While Loop

The while loop loops through a block of code as long as a specified condition is true:

Syntax

while (condition) { // code block to be executed }

Example

#include <iostream>
using namespace std;
int main(){
  int i=0;
  while (i<5)
  {
cout<<i<<"\n"; i++;
  }
  return 0;
}
//result 
1
2
3
4

The Do/While Loop

The do/while loop is a variant of the while loop. This loop will execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true.

Syntax

do { // code block to be executed } while (condition);

Example

#include <iostream>
using namespace std;
int main() {
  int i =0;
  do{
  cout<<i<<"\n";
  i++;
  } while (i<5);
  return 0;
}

C++ For Loop

When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop:

Syntax

for (statement 1; statement 2; statement 3) { // code block to be executed }

Statement 1 is executed (one time) before the execution of the code block.

Statement 2 defines the condition for executing the code block.

Statement 3 is executed (every time) after the code block has been executed.

Example

#include <iostream>
using namespace std;
int main() {
for ( int i = 0; i < 5; i++)
{
 cout<<i<<"\n";
}
  return 0;
}