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Loops


Looping statements provides a way to repeat a set of statements at a given place<./p>

Types of looping statements –

1. for loop

2. while loop

3. do while loop



1. for statement - The for statement provides a compact way to iterate over a range of values.

For loop is used to repeatedly loops until a particular condition is satisfied

for(initialization; termination; increment)
{
   statement(s)
}
 


#include <iostream>
using namespace std;
int main(){
   for(int i=1; i<=5; i++){
      
      cout << "Value of variable i is: " << i << endl;
   }
   return 0;
}


Value of variable i is: 1
Value of variable i is: 2
Value of variable i is: 3
Value of variable i is: 4
Value of variable i is: 5


2. while statement – The while statement continually executes a block of statements while a particular condition is true. Its syntax can be expressed as -

while(expression){
   statement(s)
}

The while statement evaluates expression, which must return a boolean value, If the expression evaluates to true, the while statement executes the statement(s) in the while block.


#include <iostream>
using namespace std;

int main() 
{
    float number, sum = 0;
    
    do {
        cout << "Enter a number: ";
        cin >> number;
        sum += number;
    }
    while(number != 0);

    cout << "Total sum = " << sum;
    
    return 0;
}


Output:

Enter a number: 43
Enter a number: 2
Enter a number: 5
Enter a number: 10
Enter a number: 0
Total sum = 60




3. do - while statement – do - while evaluates its expressions at the bottom of the loop instead of the top. The statements within the doblock are always executed at least once.

do{
	statement(s)
}while(expression);
#include <iostream>
using namespace std;
int main() {
	
	int x = 5;
	do {
		cout << "X is: " << x << endl;
		x = x + 1;
	} while (x < 10);
	return 0;
}


Output:

X is: 5
X is: 6
X is: 7
X is: 8
X is: 9