# While loops

> Source: https://learn-c.net/while-loops/
> Part of Learn C, free to read.

While loops are similar to for loops, but have less functionality. A while loop continues executing the while block as long as the
condition in the while remains true. For example, the following code will execute exactly ten times:

```c
int n = 0;
while (n < 10) {
    n++;
}
```

While loops can also execute infinitely if a condition is given which always evaluates as true (non-zero):

```c
while (1) {
   /* do something */
}
```

### Loop directives

There are two important loop directives that are used in conjunction with all loop types in C - the `break` and `continue` directives.

The `break` directive halts a loop after ten loops, even though the while loop never finishes:

```c
int n = 0;
while (1) {
    n++;
    if (n == 10) {
        break;
    }
}
```

In the following code, the `continue` directive causes the `printf` command to be skipped, so that only even numbers are printed out:

```c
int n = 0;
while (n < 10) {
    n++;

    /* check that n is odd */
    if (n % 2 == 1) {
        /* go back to the start of the while block */
        continue;
    }

    /* we reach this code only if n is even */
    printf("The number %d is even.\n", n);
}
```