.PHP File Format – Statements

if, elseif, else

if ( condition ) statement { elseif ( condition ) statement } [ else statement ]

A statement may be a single statement or a block. else if written as two words is an else whose statement is another if; it works with braces. In the colon form else if is a parse error and elseif must be used.

while and do-while

while ($i < 3) { $i++; }

do {
    $i--;
} while ($i > 0);

while tests the condition first. do-while tests it after running the body, so the body runs at least once. do-while has no colon form.

for

for ( [init {, init}] ; [test {, test}] ; [step {, step}] ) statement

The first group runs once. The test group runs before each iteration, and the last of its comma-separated expressions decides whether to continue. Any group can be empty, and an empty test counts as true, so for (;;) is an endless loop.

foreach

foreach ($array as $value) { /* ... */ }
foreach ($array as $key => $value) { /* ... */ }
foreach ($array as &$value) { $value *= 2; }
unset($value);
foreach ($rows as [$id, $name]) { /* ... */ }
foreach ($rows as ['id' => $id]) { /* ... */ }

• Arrays and objects can be iterated. An object gives its visible properties, or, if it implements Traversable, the values of its iterator. Other types give a warning.
• A by-value loop iterates over the array as it was when the loop started. Changes to the array inside the loop do not affect the elements visited.
• A by-reference loop works on the live array, so elements added during the loop are visited. Afterwards the loop variable still refers to the last element, so call unset() on it.
• foreach does not move the internal array pointer used by current() and next().
• The destructuring forms need PHP 5.5 with list() and PHP 7.1 with square brackets.

switch

switch ($value) {
    case 1:
    case 2:
        echo "one or two";
        break;
    default:
        echo "something else";
}

• The subject is evaluated once, and compared with each case expression using ==, in order. match is the strict, expression-based alternative.
• Without break, execution continues into the statements of the next case. Empty cases can be stacked.
• default runs if no case matches. It may be placed anywhere; more than one default is a compile error.
• A case ended with a semicolon rather than a colon is deprecated since PHP 8.5.
• Inside a switch, continue behaves like break. PHP warns about it, and continue 2 is usually meant.

break and continue

break leaves the current for, foreach, while, do-while or switch. continue starts the next iteration of a loop. Both take an optional positive integer for how many enclosing structures to act on:

foreach ($rows as $row) {
    foreach ($row as $cell) {
        if ($cell === null) {
            continue 2;  // next row
        }
    }
}

The level must be a literal positive integer: a variable, or break 0, is a compile error. Using either statement outside a loop or switch is a compile error.

return

return ends the current function and gives its value. In a file included with include or require, a top-level return stops running that file and hands the value to the includer. In the main script it ends the script. See Functions and Include.

goto

goto label; jumps to label: in the same file and the same function (PHP 5.3). A label is an identifier followed by a colon. It is case-sensitive.

for ($i = 0; $i < 100; $i++) {
    while ($j--) {
        if ($j === 17) {
            goto found;
        }
    }
}
echo 'not found';

found:
echo 'j reached 17';

• The target must be in the same function or the top level of the same file. A label in another function is an error.
• Jumping into a loop or switch is a compile error. Jumping out of one is allowed.
• The label cannot be a variable.

declare

A declare statement sets compile-time directives for the rest of the file or for a block. strict_types, encoding and ticks are described under Declare directives.

Alternative syntax

Control structures can use a colon instead of an opening brace and a keyword instead of a closing brace. It is used mainly in templates, where closing keywords are easier to read across HTML.

• Braces and the colon form cannot be mixed in one structure.
• do-while has no alternative form.
• Nothing, not even white space, may be output between switch (…): and the first case. A line break directly after ?> is fine, because the closing tag removes it.

<?php if ($items): ?>
  <ul>
  <?php foreach ($items as $item): ?>
    <li><?= htmlspecialchars($item) ?></li>
  <?php endforeach; ?>
  </ul>
<?php else: ?>
  <p>Nothing here.</p>
<?php endif; ?>

Other statements