Loops

The for loop

rcaron
for ($i = 0; $i < 5; $i++) {
    print $i;
}
// Outputs 0 1 2 3 and 4
// $i is still accesible
// Outputs 5
print $i;

rcaron
for ($i = 0; $i < 5; $i++) {
    print $i;
}
// Outputs 0 1 2 3 and 4
// $i is still accesible
// Outputs 5
print $i;

警告

Note that in C# the initializer and iterator can have multiple expressions separated by ,, RCaron does not support this yet.

• The initializer section($i = 0) is executed only once. It is executed in the current scope, meaning that it is accessible outside the loop body as demonstrated in the example.
• The condition section($i < 5) determines whether the loop should continue or not. If false the loop cancels.
• The iterator section($i++) is executed after each execution of the loop body.

The qfor loop

The for statement except it uses a single scope for all of the loop body runs. It is unsafe since variables from the previous run of the loop body can be accessed by the next.

The foreach loop

The foreach statement executes a code block for each element provided by the enumerator of a type that implements IEnumerable.

备注

The right side of the foreach can also be an IEnumerator.

备注

Note the type has to implement IEnumerable while C# only requires the type to have a parameterless GetEnumerator and blablabla.

rcaron
foreach ($num in @(0, 1, 2, 3)) {
    print $num;
}
// Outputs 0 1 2 and 3

rcaron
foreach ($num in @(0, 1, 2, 3)) {
    print $num;
}
// Outputs 0 1 2 and 3

The while loop

The while statement executes it's body zero or more times as long as it's condition is true.

rcaron
$n = 0;
while ($n < 4) {
    print $n;
    $n++;
}
// Outputs 0 1 2 and 3

rcaron
$n = 0;
while ($n < 4) {
    print $n;
    $n++;
}
// Outputs 0 1 2 and 3

The dowhile loop

The dowhile statement executes it's body at least once and continues as long as it's condition is true.

rcaron
$n = 0;
dowhile ($false) {
    print $n;
    $n++;
}
// Outputs 0

rcaron
$n = 0;
dowhile ($false) {
    print $n;
    $n++;
}
// Outputs 0

The loop loop

The loop loop continues with no condition. It just continues. Only way to escape out of it is the break statement.

rcaron
$n = 0;
loop {
    print $n;
    if ($n == 5) {
        break;
    }
    $n++;
}
// Outputs 0 1 2 3 4 and 5

rcaron
$n = 0;
loop {
    print $n;
    if ($n == 5) {
        break;
    }
    $n++;
}
// Outputs 0 1 2 3 4 and 5