array_merge函数解释

键名相同且必须是字符

$a = array("w"=>1,1,2,3,4);
$b = array("w"=>2,1,2,3,5);
$a = array_merge($a,$b);
var_dump($a);

$a = array("w"=>1,1,2,3,4);
$b = array("w"=>2,1,2,3,5);
$a = array_merge($a,$b);
var_dump($a);

这样写被不被认为是字符,且还会在后面添加

$a = array("1"=>1,1,2,3,4);
$b = array("1"=>2,1,2,3,5);
$a = array_merge($a,$b);
var_dump($a);

案例

<?php 
$school=[
  'class'=>[
    '一班'=>[
      'name'=>['小明','小红','小刚'],
      'sex'=>['男','女','男'],
    ],
    '三班'=>[
      'name'=>['小步','小心','小美'],
      'sex'=>['男','女','女'],
    ]
  ],
];
$fu=[
  '一班'=>[
    'name'=>['小白'],
    'sex'=>['男'],
  ],
   
  '三班'=>[
    'name'=>['小可'],
    'sex'=>['女'],
  ],
];
//先判断是否是一个班级的
//然后按名字覆盖
//性别覆盖
foreach($school['class'] as $k1=>$vo1){
 foreach($fu as $k2=>$vo2){
  if($k1==$k2){
   $school['class'][$k2]['name'] =array_merge($vo1['name'],$vo2['name']);
   $school['class'][$k2]['sex'] = array_merge($vo1['sex'],$vo2['sex']);
   
  }else{
  }
 }
}
echo "<pre>";
var_dump($school['class']);