> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/NormandoRamirezDelgado/6C-Febrero-2026/llms.txt
> Use this file to discover all available pages before exploring further.

# While Loops

> Learn how to use while loops for conditional iteration in Dart

## Overview

While loops execute a block of code repeatedly as long as a condition remains true. Unlike for loops, while loops are ideal when you don't know in advance how many iterations are needed.

## Basic Syntax

```dart theme={null}
while (condition) {
  // Code to execute
}
```

<Note>
  The condition is checked **before** each iteration. If the condition is false initially, the loop body never executes.
</Note>

## Incrementing While Loop

A basic while loop that increments a counter:

```dart theme={null}
int contador = 1;
print('\nCiclo While Incremento');

while (contador <= 5) {
  print('Contador: $contador');
  contador++;
}
// Output: Contador: 1
//         Contador: 2
//         Contador: 3
//         Contador: 4
//         Contador: 5
```

## Decrementing While Loop

You can also decrement the counter:

```dart theme={null}
print('\nCiclo While Decremento');
int contador = 5;

while (contador >= 1) {
  print('Contador: $contador');
  contador--;
}
// Output: Contador: 5
//         Contador: 4
//         Contador: 3
//         Contador: 2
//         Contador: 1
```

## Complete Example

```dart theme={null}
void main() {
  int contador = 1;
  print('\nCiclo While Incremento');
  
  while (contador <= 5) {
    print('Contador: $contador');
    contador++;
  }

  // Decrement
  print('\nCiclo While Decremento');
  contador = 5;
  
  while (contador >= 1) {
    print('Contador: $contador');
    contador--;
  }
}
```

## When to Use While Loops

<Steps>
  <Step title="Unknown iteration count">
    Use while loops when the number of iterations depends on runtime conditions rather than a fixed count.
  </Step>

  <Step title="Condition-based execution">
    While loops are ideal when you need to continue until a specific condition is met.
  </Step>

  <Step title="Reading input">
    Useful for reading user input or processing data until a sentinel value is encountered.
  </Step>
</Steps>

## While vs For Loops

### Use For Loop When:

* You know the exact number of iterations
* You're iterating over a range of numbers
* You're iterating over a collection

### Use While Loop When:

* The number of iterations is unknown
* The loop depends on external conditions
* You're waiting for a specific state to occur

## Common Patterns

### Counting up

```dart theme={null}
int i = 0;
while (i < n) {
  // Code
  i++;
}
```

### Counting down

```dart theme={null}
int i = n;
while (i > 0) {
  // Code
  i--;
}
```

### Condition-based

```dart theme={null}
while (someCondition) {
  // Code that may change someCondition
}
```

## Loop Control

<Tip>
  Use `break` to exit the loop early and `continue` to skip the current iteration:

  ```dart theme={null}
  int contador = 0;
  while (contador < 10) {
    contador++;
    
    if (contador == 5) {
      continue; // Skip 5
    }
    
    if (contador > 7) {
      break; // Exit at 8
    }
    
    print(contador);
  }
  ```
</Tip>

## Infinite Loops

<Warning>
  Be careful to avoid infinite loops! Always ensure the condition will eventually become false:

  ```dart theme={null}
  // DANGER: Infinite loop!
  int x = 1;
  while (x > 0) {
    print(x);
    x++; // x will never be <= 0
  }
  ```
</Warning>

## Best Practices

* Always initialize the loop variable before the loop
* Ensure the condition will eventually become false
* Update the loop variable inside the loop body
* Use meaningful variable names
* Consider using for loops when the iteration count is known
* Add safety mechanisms (like maximum iteration counts) for potentially infinite loops

## Practical Example

Here's a practical example of reading values until a condition is met:

```dart theme={null}
void main() {
  int sum = 0;
  int count = 1;
  
  // Sum numbers from 1 to 10
  while (count <= 10) {
    sum += count;
    count++;
  }
  
  print('Sum of numbers 1-10: $sum');
  // Output: Sum of numbers 1-10: 55
}
```