如何将多个数组与相同的键组合？

I have an array like this. There are some array with the same name. Such as Grant 1, Grant 2... and they have many Projects that should be in the same place. For example: Grant 1 should contain the information that belongs to Grant 1. The same thing that should happen to Grant 2. And so on

array:5 [▼
  0 => array:2 [▼
    0 => "Grant 1"
    1 => Project {#423 ▶}
  ]
  1 => array:2 [▼
    0 => "Grant 1"
    1 => Project {#421 ▶}
  ]
  2 => array:2 [▼
    0 => "Grant 2"
    1 => Project {#412 ▶}
  ]
  3 => array:2 [▼
    0 => "Grant 1"
    1 => Project {#424 ▶}
  ]
  4 => array:2 [▼
    0 => "Grant 2"
    1 => Project {#419 ▶}
  ]
]

I want to combine them to:

array:5 [▼
  0 => array:2 [▼
    0 => "Grant 1"
    1 => Project {#423 ▶}
    2 => Project {#421 ▶}
    3 => Project {#424 ▶}
  ]
  1 => array:2 [▼
    0 => "Grant 1"        
    1 => Project {#412 ▶}
    2 => Project {#419 ▶}
  ]
]

Please help. Thanks,

I think you can use foreach:

$newArray = [];
foreach ($array as $value) {
    $newArray[$value[0]][] = $value[1];
}

And you have array like this:

array:5 [▼
  "Grant 1" => array:2 [▼
    1 => Project {#423 ▶}
    2 => Project {#421 ▶}
    3 => Project {#424 ▶}
  ]
  "Grant 2" => array:2 [▼ 
    1 => Project {#412 ▶}
    2 => Project {#419 ▶}
  ]
]

Or something like this(thanks @AbraCadaver):

$newArray = [];
foreach ($array as $value) {
    if (isset($newArray[$value[0]] {
        $newArray[$value[0]][] = $value[1];
    } else {
        $newArray[$value[0]] = $value;
    }
}

Array what you need:

array:5 [▼
    0 => array:2 [▼
        0 => "Grant 1"
        1 => Project {#423 ▶}
        2 => Project {#421 ▶}
        3 => Project {#424 ▶}
  ]
    1 => array:2 [▼
        0 => "Grant 1"        
        1 => Project {#412 ▶}
        2 => Project {#419 ▶}
  ]
]