[9.x] Convert closures to arrow functions (#46076)

* formating

* Apply fixes from StyleCI

---------

Co-authored-by: Valodia <[email protected]>

Author: xurshudyan

src/Illuminate/Collections/Arr.php

@@ -838,9 +838,7 @@ public static function where($array, callable $callback)
      */
     public static function whereNotNull($array)
     {
-        return static::where($array, function ($value) {
-            return ! is_null($value);
-        });
+        return static::where($array, fn ($value) => ! is_null($value));
     }
 
     /**

src/Illuminate/Collections/Collection.php

@@ -84,11 +84,9 @@ public function avg($callback = null)
     {
         $callback = $this->valueRetriever($callback);
 
-        $items = $this->map(function ($value) use ($callback) {
-            return $callback($value);
-        })->filter(function ($value) {
-            return ! is_null($value);
-        });
+        $items = $this
+            ->map(fn ($value) => $callback($value))
+            ->filter(fn ($value) => ! is_null($value));
 
         if ($count = $items->count()) {
             return $items->sum() / $count;
@@ -349,14 +347,10 @@ public function duplicatesStrict($callback = null)
     protected function duplicateComparator($strict)
     {
         if ($strict) {
-            return function ($a, $b) {
-                return $a === $b;
-            };
+            return fn ($a, $b) => $a === $b;
         }
 
-        return function ($a, $b) {
-            return $a == $b;
-        };
+        return fn ($a, $b) => $a == $b;
     }
 
     /**
@@ -1633,13 +1627,9 @@ public function values()
      */
     public function zip($items)
     {
-        $arrayableItems = array_map(function ($items) {
-            return $this->getArrayableItems($items);
-        }, func_get_args());
+        $arrayableItems = array_map(fn ($items) => $this->getArrayableItems($items), func_get_args());
 
-        $params = array_merge([function () {
-            return new static(func_get_args());
-        }, $this->items], $arrayableItems);
+        $params = array_merge([fn () => new static(func_get_args()), $this->items], $arrayableItems);
 
         return new static(array_map(...$params));
     }

src/Illuminate/Collections/LazyCollection.php

@@ -430,9 +430,7 @@ public function except($keys)
     public function filter(callable $callback = null)
     {
         if (is_null($callback)) {
-            $callback = function ($value) {
-                return (bool) $value;
-            };
+            $callback = fn ($value) => (bool) $value;
         }
 
         return new static(function () use ($callback) {
@@ -1500,9 +1498,7 @@ public function takeWhile($value)
         /** @var callable(TValue, TKey): bool $callback */
         $callback = $this->useAsCallable($value) ? $value : $this->equality($value);
 
-        return $this->takeUntil(function ($item, $key) use ($callback) {
-            return ! $callback($item, $key);
-        });
+        return $this->takeUntil(fn ($item, $key) => ! $callback($item, $key));
     }
 
     /**