Dart While Loop

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Syntax

while (condition) {
  // Statements to execute
}

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Execution Mechanics

1. Condition Evaluation: The loop begins by evaluating the condition expression. In Dart, this expression must evaluate strictly to a boolean (bool) type. Dart does not support implicit truthy/falsy type coercion (e.g., while (1) will result in a compile-time error).
2. Execution: If the condition evaluates to true, the statements within the loop body are executed sequentially.
3. Iteration: After the loop body completes, control flow returns to the top of the loop, and the condition is re-evaluated.
4. Termination: The loop terminates immediately when the condition evaluates to false. Control flow then passes to the first statement following the loop block.

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Code Example

int counter = 0;

while (counter < 3) {
  print(counter);
  counter++; // State mutation to ensure eventual termination
}

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Control Transfer Statements

• break: Immediately terminates the loop entirely, bypassing the condition check and transferring execution to the code following the loop block.
• continue: Halts the current iteration, skips any remaining statements in the loop body, and immediately jumps back to re-evaluate the loop condition.

int i = 0;

while (i < 5) {
  i++;
  if (i == 2) {
    continue; // Skips the rest of the block, re-evaluates (i < 5)
  }
  if (i == 4) {
    break; // Exits the loop entirely
  }
  print(i);
}

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Infinite Loops

// Example of an infinite loop
while (true) {
  // This block will execute forever unless a 'break' statement is encountered
}