Do While Loop in Dart

Do While Loop

Do while loop is used to run a block of code multiple times. The loop’s body will be executed first, and then the condition is tested. The syntax of do while loop is:

do{
    statement1;
    statement2;
    .
    .
    .
    statementN;
}while(condition);

• First, it runs statements, and finally, the condition is checked.
• If the condition is true, the code inside {} is executed.
• The condition is re-checked until the condition is false.
• When the condition is false, the loop stops.

Example 1: To Print 1 To 10 Using Do While Loop

void main() {
  int i = 1;
  do {
    print(i);
    i++;
  } while (i <= 10);
}

1
2
3
4
5
6
7
8
9
10

Example 2: To Print 10 To 1 Using Do While Loop

void main() {
  int i = 10;
  do {
    print(i);
    i--;
  } while (i >= 1);
}

10
9
8
7
6
5
4
3
2
1

Example 3: Display Sum of n Natural Numbers Using Do While Loop

Here, the value of the total is 0 initially. Then, the do-while loop is iterated from i = 1 to 100. In each iteration, i is added to the total, and the value of i is increased by 1. Result is 1+2+3+….+99+100.

void main(){

  int total = 0;
  int n = 100; // change as per required
  int i =1;
  
  do{
  total = total + i;
    i++;
  }while(i<=n);
  
  print("Total is $total");
  
}

Total is 5050

When The Condition Is False

Let’s make one condition false and see the demo below. Hello got printed if the condition is false.

void main(){

  int number = 0;
  
  do{
  print("Hello");
  number--;
  }while(number >1);
  
}

Hello

Video

Watch our video on while loop in Dart.