Elvis Operator Not Used

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TL;DR

Explanation

PHP 5.3 introduced the shorthand ternary (Elvis) operator: $x ?: $y is equivalent to $x ? $x : $y. It eliminates repeating the condition variable. Note: ?: triggers E_NOTICE for undefined variables — for null checks on potentially undefined keys use ?? instead. Use ?: when the variable is defined and you want the first truthy value; use ?? when the variable may be undefined and you want the first non-null value.

Common Misconception

Why It Matters

Common Mistakes

• $value ? $value : $default when $value ?: $default is cleaner.
• Using ?: instead of ?? for array keys — $arr['key'] ?: 'default' triggers a notice if 'key' doesn't exist.
• ?: for nullable values where 0 or '' should not trigger the fallback — use ?? instead.
• Chaining ternaries without using ?: making the intent unclear.

Code Examples

// Repetition — same variable twice:
$title       = $post->title    ? $post->title    : 'Untitled';
$displayName = $user->name     ? $user->name     : 'Anonymous';
$port        = $config['port'] ? $config['port'] : 8080;
// Also: $port uses ?: which replaces 0 — bug if port 0 is valid

// Elvis operator — no repetition:
$title       = $post->title ?: 'Untitled';
$displayName = $user->name  ?: 'Anonymous';

// But: use ?? when value may be null or undefined:
$port = $config['port'] ?? 8080; // 0 is a valid port — use ??

// Correct pairing:
// ?: for 'first truthy value' (0/false/'' trigger fallback)
// ?? for 'first non-null value' (0/false/'' do NOT trigger fallback)

References

• ↗ https://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary

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