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.
Info

Note: In a do-while loop, the statements will be executed at least once time, even if the condition is false. It is because the statement is executed before checking the condition.

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

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

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

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

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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");
  
}

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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);
  
}

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Video

Watch our video on while loop in Dart.