用for给数组赋值解决思路

$tests=array(id => "910003", params => array("param1" => '', "param2" => '', "param3" => ''));

for ($i = 0; $i <= count($tests["params"]); $i++) {
   
}

$tests = array('id' => "910003", 'params' => array("param1" => '', "param2" => '', "param3" => ''));
foreach($tests["params"] as $k=>&$t) $t = $k;
print_r($tests);

Array
(
    [id] => 910003
    [params] => Array
        (
            [param1] => param1
            [param2] => param2
            [param3] => param3
        )
)

$tests = array('id' => "910003", 'params' => array("param1" => '', "param2" => '', "param3" => ''));
for($i=1; $i<=count($tests["params"]); $i++) {
  $tests["params"]['param'.$i] = $i;
}
print_r($tests);

Array
(
    [id] => 910003
    [params] => Array
        (
            [param1] => 1
            [param2] => 2
            [param3] => 3
        )
)