PHP - 如果我只能在一次调用中获取100个项目，是否有一种循环遍历JSON文件中所有元素的方法？

Question

I need to display all the elements/objects of a JSON file. I can currently only call an endpoint that takes an offset (starting index) and limit. The maximum number of elements you could get is 100 (the limit) at one call. I was wondering how could I get all of the elements of a JSON file and store them in an array without knowing how many elements there are in the JSON file.

Initially I tried to save the first 500 elements in an array. The problem with that was that the output size of that array was 5 and not 500 because the getElements endpoint returns a list of 100 elements, so what the array actually stored was 100 elements at each index. So for example json_array[0] contains the first 100 elements, json_array[2] contains the next 100 elements etc.

$offset = 0;
$limit = 100;
$json_array = array();

while($offset < 500)
{
array_push($json_array,getElements($token,"api/Elements?offset=".$offset."&limit=".$limit));
$offset+=100;
}

echo count($json_array)

I am expecting to find a way to loop through the entire json file without knowing the number of elements that the file has. My final expectation is to find a way to display the number of all of these elements. Thank you!

Answer 1

I work with a similar API - there is a per_page option and a page option.

Fortunately, the API I'm hitting is set up to return everything with no error if there are less results than the per_page value, so what I do is simply loop while I fetched 100 records.

Something like:

$fetched=100;
$page=0;
$per_page=100;
$total_result=array();
while($fetched==100){

  $res=json_decode(file_get_contents($API_URL."?offset=".($page*$per_page));

  $fetched=count($res);

  // add res to big result set
  for($i=0;$i<$fetched;$i++){
     $total_result[]=$res[$i];
  }

  $page++;   
}