[5.8] Add join method to collection

src/Illuminate/Support/Collection.php

@@ -296,6 +296,36 @@ public function containsStrict($key, $value = null)
         return in_array($key, $this->items, true);
     }
 
+    /**
+     * Join all items from the collection using a string. The final items can use a separate glue string.
+     *
+     * @param  string  $glue
+     * @param  string  $finalGlue
+     * @return string
+     */
+    public function join($glue, $finalGlue = '')
+    {
+        if ($finalGlue === '') {
+            return $this->implode($glue);
+        }
+
+        $count = $this->count();
+
+        if ($count === 0) {
+            return '';
+        }
+
+        if ($count === 1) {
+            return $this->last();
+        }
+
+        $collection = new static($this->items);
+
+        $finalItem = $collection->pop();
+
+        return $collection->implode($glue).$finalGlue.$finalItem;
+    }
+
     /**
      * Cross join with the given lists, returning all possible permutations.
      *

tests/Support/SupportCollectionTest.php

@@ -878,6 +878,19 @@ public function testCollapseWithNestedCollections()
         $this->assertEquals([1, 2, 3, 4, 5, 6], $data->collapse()->all());
     }
 
+    public function testJoin()
+    {
+        $this->assertEquals('a, b, c', (new Collection(['a', 'b', 'c']))->join(', '));
+
+        $this->assertEquals('a, b and c', (new Collection(['a', 'b', 'c']))->join(', ', ' and '));
+
+        $this->assertEquals('a and b', (new Collection(['a', 'b']))->join(', ', ' and '));
+
+        $this->assertEquals('a', (new Collection(['a']))->join(', ', ' and '));
+
+        $this->assertEquals('', (new Collection([]))->join(', ', ' and '));
+    }
+
     public function testCrossJoin()
     {
         // Cross join with an array