EC
OutOfBoundsException
PHPERRORCommonBounds

Value not in valid range at runtime

Quick Answer

Check index bounds before accessing elements; throw OutOfBoundsException in custom data structures for out-of-range access.

What this means

Thrown when a runtime value falls outside the acceptable bounds of a container or range. Use for index-out-of-range conditions in custom data structures.

Why it happens
  1. 1Accessing an index beyond the end of a custom collection
  2. 2Negative index in a bounded container

Fix

Bounds check in custom collection

Bounds check in custom collection
public function get(int $index): mixed {
    if ($index < 0 || $index >= count($this->items)) {
        throw new \OutOfBoundsException("Index $index out of bounds [0, " . count($this->items) . ")");
    }
    return $this->items[$index];
}

Why this works

Explicit bounds check with a descriptive message makes the error actionable.

Code examples
SplFixedArray accessphp
$arr = new \SplFixedArray(5);
$arr[10]; // RuntimeException (PHP throws this for SplFixedArray)
Custom throwphp
if (!isset($this->stack[$n])) {
    throw new \OutOfBoundsException("Stack index $n does not exist");
}

Content generated with AI assistance and reviewed for accuracy. Found an error? hello@errcodes.dev

← All PHP errors