Yaya kake bayyana ayyukan da nau'i da abubuwa na tsohuwa?

Question

Accepted Answer

Ana bayyana ayyukan PHP tare da kalmar sermica `function`. PHP na zamani yana goyan bayan **sanarwar nau'i** akan sigine da dawo darajar, **darajar tsohuwa**, da sigine masu muhimmi — sa da ayyuka su kasua kuma su bayyana kansu.

## Ayyukan asali tare da sanarwar nau'i

```php
<?php
// modern PHP — typed parameters and a typed return
function add(int $a, int $b): int {
    return $a + $b;
}

function greet(string $name, string $greeting = "Hello"): string {  // default value
    return "$greeting, $name";
}

greet("Ann");              // "Hello, Ann"
greet("Ann", "Hi");        // "Hi, Ann"
```

Sanarwar nau'i (`int $a`, nau'in dawo `: int`) yi PHP za a bincika sigine da nau'in dawo — kama cikas da bayyana al'amari. Darajar tsohuwa sai sigine masu wuri.

## Nau'i masu baci da nau'i na yada (PHP 8+)

```php
function find(?int $id): ?User {        // ? = nullable (int|null, User|null)
    return $id ? lookup($id) : null;
}

function process(int|string $input): void {   // union type — int OR string (PHP 8)
    // ...
}
```

`?Type` ya bade null; **nau'i na yada** (`int|string`, PHP 8) ya bade nau'i da yawa — sa sayyadi zama daidai.

## Sigine mai muhimmi da sun suna (Jigon alamun)

```php
function sum(int ...$numbers): int {     // variadic — any number of int args
    return array_sum($numbers);
}
sum(1, 2, 3);            // 6

// named arguments (PHP 8) — pass by parameter name, skip optional ones
greet(name: "Ann", greeting: "Hey");
```

## Nau'i tsattsautsa (a damre)

```php
<?php
declare(strict_types=1);    // at the top of the file — enforce STRICT type checking

add("5", 3);   // ❌ TypeError with strict_types (without it, "5" would coerce to 5)
```

`declare(strict_types=1)` sai sanarwar nau'i su kasua — PHP za a ki nau'i ba sadarwa ya ba tafi daidai, wanda shi ne al'amarin zamani a damre don kama cikas.

## Yaya shi gida mahimmanci

Tunani bayyana ayyukan PHP na zamani — musamman **sanarwar nau'i** — mahimmanci ne don rubuta kwastare, kwastare tsari, kuma yi nuni ya yi PHP ya kawo daga asalinsa mara watayi.

Sigine tare da sanarwar nau'i da dawo darajar (tare da nau'i masu baci da yada) sai ayyuka su bayyana kansu kuma ya bada dama PHP ta kama cikas nau'i, yayin da darajar tsohuwa da suna sigine da masu muhimmi sai samun sayyadi masu zuwa, kasua.

Mahimmancin al'amarin zamani ne **`declare(strict_types=1)`**, wanda ya aiwata sanarwar nau'i tsattsautsa (ba tafi daidai a ba tafi daidai baaj ba shi yin ita baaj) — kayan mahimmanci don kama cikas jiya da rubuta tsari masu aminci.

Sanin yaya a bayyana ayyuka da sanarwar nau'i tare da tsohuwa, da amfani da nau'i tsattsautsa, shine ilimin kullun na zamani, kwastare, PHP cike, wanda ya bada wajen tsarin aminci daga nau'i mara watayi na PHP na tsohuwa.