6 PHP 8 Features You Should Be Using in 2026

1. Constructor property promotion

class User {
    public function __construct(
        public string $name,
        public string $email
    ) {}
}

2. Named arguments

setcookie(name: 'token', value: $t, httponly: true);

3. Nullsafe operator

$city = $user?->address?->city;

4. match expression

$label = match($status) {
    1 => 'Active',
    2 => 'Pending',
    default => 'Unknown',
};

5. Enums (PHP 8.1+)

enum Status: int {
    case Active = 1;
    case Pending = 2;
}

6. Readonly properties (PHP 8.1+)

public readonly int $id;

match throws an error for unmatched values without a default, unlike switch, which quietly falls through. That catches bugs earlier.

Which feature do you use most? Drop a comment, and share this with a PHP developer still writing PHP 5 style code.

 Most PHP developers learn MySQL by trial and error, which means a lot of bad habits get baked into production code early and never get questioned. Here are the ten most common mistakes that quietly wreck performance as your application scales.

10 MySQL Mistakes

1. Using SELECT * Instead of Named Columns

-- Bad
SELECT * FROM users WHERE id = 1;

-- Good
SELECT id, name, email FROM users WHERE id = 1;

SELECT * pulls unnecessary data over the wire and prevents MySQL from using covering indexes effectively.

2. Not Using Prepared Statements

// Vulnerable to SQL injection
$query = "SELECT * FROM users WHERE email = '$email'";

// Safe and reusable
$stmt = $pdo->prepare("SELECT * FROM users WHERE email = ?");
$stmt->execute([$email]);

Beyond security, prepared statements let MySQL cache the query execution plan, improving performance on repeated queries.

3. Missing Indexes on Foreign Keys
A shocking number of production databases have foreign key columns with no index at all, turning every JOIN into a full table scan.

4. N+1 Query Problem

// Bad - runs 1 query + N queries in a loop
foreach ($orders as $order) {
    $items = getItemsByOrderId($order['id']);
}

// Good - one query with a JOIN
$query = "SELECT o.*, i.* FROM orders o 
          JOIN items i ON i.order_id = o.id";

5. Using LIKE '%keyword%' on Large Tables
Leading wildcards prevent MySQL from using indexes at all. For real search functionality, use MySQL's FULLTEXT indexes or a dedicated search engine like Elasticsearch.

6. Storing Passwords Without Proper Hashing

// Never do this
$password = md5($_POST['password']);

// Always do this
$password = password_hash($_POST['password'], PASSWORD_DEFAULT);

7. Not Closing Database Connections
Long-running scripts that don't explicitly close connections can exhaust MySQL's max_connections limit under load.

8. Ignoring EXPLAIN on Slow Queries
Running EXPLAIN SELECT ... before deploying a query takes 10 seconds and can reveal missing indexes or full table scans before they hit production.

9. Storing Dates as Strings

-- Bad
created_at VARCHAR(20)

-- Good
created_at DATETIME

String dates break sorting, filtering, and date arithmetic, and they're a common source of subtle bugs.

10. Not Using Connection Pooling in High-Traffic Apps
Opening a fresh MySQL connection on every request is expensive. For high-traffic PHP apps, persistent connections or a pooling layer significantly reduce overhead.

Found a mistake you're guilty of? Drop a comment — and share this with a junior dev on your team before it costs you a production incident.

Banning things reflects cultural values — and sometimes produces surprising results.

Unusual Bans Around the World

Chewing Gum in Singapore

Singapore banned the import and sale of chewing gum in 1992. The reason: gum stuck to public surfaces, causing maintenance issues. Exceptions exist for therapeutic gum (prescribed by doctors).

Diamonds in Russia

During the Soviet era, citizens were discouraged from wearing diamonds publicly. The government viewed them as Western capitalist symbols. Owning large diamonds was considered suspicious.

Hamas in Many Countries

Hamas is designated a terrorist organization by many Western countries. Various forms of the group are banned across Europe, North America, and elsewhere.

Baby Walkers in Canada

Canada banned baby walkers in 2004, citing safety concerns. Babies can fall down stairs, reach dangerous objects, or tip the walker over. The ban applies to selling, importing, and advertising them.

Pet Fish in Romania

Romania previously banned goldfish as pets, though enforcement was unclear. The rationale was that keeping fish in small bowls was considered animal cruelty.

Knives in Public in Various Countries

Several countries including the UK, Australia, and others restrict carrying knives in public spaces. Specific blade lengths and types vary.

Why They Ban Things

• Public safety — baby walkers, knives
• Cultural values — diamonds in Soviet Russia
• Public order — gum in Singapore
• Animal welfare — fish in Romania
• Terrorism — political organizations

For decades, some of the most notorious crimes went unsolved. DNA technology changed that.

Cases Cracked

The Golden State Killer

For over 30 years, the Golden State Killer (later called the East Area Rapist) terrorized California. At least 13 murders, 50 rapes. In 2018, DNA from a crime scene was uploaded to a public genealogy database. A distant relative's DNA match identified Joseph James DeAngelo. He was arrested at age 72.

The BTK Killer

Dennis Rader killed 10 people in Kansas between 1974 and 1991. He taunted police with letters and a floppy disk. In 2005, DNA from the disk matched a family member. Rader was arrested. He is serving 10 consecutive life sentences.

Elizabeth Short (Black Dahlia)

The 1947 murder of Elizabeth Short has never been officially solved. In 2018, a retired detective claimed DNA evidence and modern genealogy pointed to a suspect. The LAPD hasn't confirmed these findings.

The Zodiac Killer

In 2018, forensic genealogists identified a suspect in the Zodiac's 1969 Lake Berryessa attack using DNA from the postage stamp. The suspect died in 2018. Police have not confirmed the findings.

How It Works

Forensic genealogists take crime scene DNA, upload it to public databases, and look for matches with people who voluntarily submitted their DNA for ancestry research. Even distant relatives can provide enough information to narrow down suspects to a specific family tree.

The Controversy

• Privacy concerns — people who never committed crimes can be identified through relatives
• Consent — genetic data was uploaded for genealogy, not law enforcement
• D数据库 coverage — databases are predominantly used by people of European descent

Some people vanish and leave almost no trace. Despite extensive searches and investigations, no explanation ever emerges.

Notable Cases

1. The Sodder Children (1945)

Five of the nine Sodder children disappeared during a fire at their family home in Fayetteville, West Virginia. The parents believed the children died, but the body was never recovered. The family never gave up hope — and the case remains officially unsolved.

2. Harold Holt (1967)

Harold Holt, the Prime Minister of Australia, went swimming at Cheviot Beach in Victoria. He never surfaced. Despite one of the largest search operations in Australian history, his body was never found.

3. The Lost City of Z

British explorer Percy Fawcett disappeared in the Amazon rainforest in 1925 while searching for a legendary lost city. He and his son Jack, along with Jack's friend Raleigh Rimell, were never found.

4. The Mary Celeste

The Mary Celeste was found adrift in the Atlantic Ocean in 1872. The ship was intact, supplies were ample, but the crew was gone — ten people and the captain's family. No one was ever found or determined to be responsible.

5. The Skeleton Coast Ships

Namibia's Skeleton Coast has dozens of shipwrecks with no crew aboard. Some date back centuries. Theories range from storms to mutiny to supernatural causes. No artifacts explain the disappearances.

Why Some Disappearances Stay Mysterious

• Remote locations — bodies in wilderness may never be found
• Water — oceans and rivers swallow evidence
• Time — evidence degrades, witnesses die
• Intentionally hidden — some disappearances are planned

Some robberies were so audacious that the criminals vanished — and the loot remained missing.

The Biggest Unsolved Heists

1. Isabella Stewart Gardner Museum (1990)

Two men dressed as Boston police officers entered the Gardner Museum through a side entrance. They subdued the guards and walked out with 13 works of art — including Rembrandt's "The Storm on the Sea of Galilee." The heist is the largest property crime in US history. The art has never been recovered.

The reward is $10 million. In 2013, the FBI announced they believed they knew the identities of the thieves but chose not to reveal them in order to protect an ongoing investigation.

2. The Central Bank of Iraq (1990)

During the Gulf War, Iraqi forces allegedly removed approximately $1 billion in gold and currency from the Central Bank of Kuwait. The scale and method remain disputed. Much of the gold was never recovered.

3. The Hatton Garden Safe Deposit Heist (2015)

In London, a gang of elderly thieves broke into the vault over Easter weekend. They accessed 73 safe deposit boxes containing an estimated $200 million in jewelry, cash, and valuables. Most of the gang was eventually caught and sentenced — but a significant portion of the loot remains unrecovered.

4. The Brink's-Mat Robbery (1983)

Gunmen robbed the Brink's-Mat warehouse at Heathrow Airport in London, taking about $26 million in gold, diamonds, and cash. Only a small fraction was ever recovered. Several people were killed in connection to the aftermath, but most of the gold has never been found.

Why They Stay Unsolved

• No witnesses — careful planning eliminates witnesses
• Clean getaway — no trail to follow
• Destroyed evidence — loot melted, sold, or hidden
• Inside help — someone within the institution facilitated entry
• Time — statute of limitations expires, witnesses die

Square airplane windows don't exist anymore. The switch happened after a series of catastrophic failures in the 1950s — and the reason is physics.

The Problem With Squares

When an airplane flies, the cabin is pressurized. Air pressure pushes outward against the fuselage. At high altitudes, the pressure difference is significant — roughly 1 atmosphere at sea level vs. a fraction at cruising altitude.

Stress concentrates at sharp corners. A square window has four 90-degree corners where stress accumulates. Repeated pressurization and depressurization during flights causes tiny cracks to grow from these corners. Eventually, the window fails.

The Solution: Circles

Round windows distribute stress evenly across the surface. No corners means no concentration points. The pressure pushes outward in every direction uniformly, and the window can handle it.

Modern airplane windows are actually made of three layers:

• Outer layer — structural, handles pressure
• Middle layer — backup structural
• Inner layer — scratch protection, non-structural

A Similar Principle Elsewhere

The same stress-distribution principle appears in many engineering contexts:

• Diving helmets — circular faceplates
• Submarine viewports — circular or oval
• Pressure cookers — round lids
• Ball bearings — distribute load evenly