fwrite() 两次写入一个 json 编码的数组

Question

我正在尝试使用通过获取请求收集的数据编写一个 json 文件。json文件是一个二维的字符串数组，但是当数据写入文件时，嵌套数组会被写入两次。<?php//used for parsing htmlinclude("simple_html_dom.php");//read the file $fp = fopen("j.json", "r");$t = fread($fp, filesize("j.json"));fclose($fp);$loaded = json_decode($t);//print the loaded arrayprint_r($loaded);//gathering the data$url = "https://www.soldionline.it/quotazioni/dettaglio/IT0003934657.html";$prezzo1 = file_get_html($url)->find("span[class=val] b", 0)->plaintext;$data = file_get_html($url)->find("span[class=ora] b", 0)->plaintext;$url = "https://www.soldionline.it/quotazioni/dettaglio/IT0003934657.html";$prezzo2 = file_get_html($url)->find("span[class=val] b", 0)->plaintext;$url = "https://www.soldionline.it/quotazioni/dettaglio/IT0003934657.html";$prezzo3 = file_get_html($url)->find("span[class=val] b", 0)->plaintext;//adding the new data to the arrayarray_push($loaded, array($prezzo1, $prezzo2, $prezzo3, $data));//the new json string is parsed and ready to be written$s = json_encode($loaded);//printing stuff to ensure the data is correctecho "<br>".$s.", type=".gettype($s)."<br>";print_r($loaded);//write the new json string to the same file$fp = fopen("j.json", "w");fwrite($fp, $s);fclose($fp);?>j.json 在脚本运行之前：[]脚本打印的内容：Array ( )[["128,54","128,54","128,54","30\/12"]], type=stringArray ( [0] => Array ( [0] => 128,54 [1] => 128,54 [2] => 128,54 [3] => 30/12 ) )脚本后的 j.json：[["128,54","128,54","128,54","30\/12"],["128,54","128,54","128,54","30\/12"]]我尝试像这样打开文件：$fp = fopen("j.json", "r+");然后我更改了脚本：$s = "\"".json_encode($loaded)."\"";echo "<br>".$s.", type=".gettype($s)."<br>";print_r($loaded);fwrite($fp, $s);fclose($fp);我发现也写了一个空值：[]"[["128,54","128,54","128,54","30\/12"]]""null"

Answer 1

浏览器在访问 url 时发送两个请求，一个对 php 文件的请求，另一个对/favicon.ico. 发送第二个请求以检查站点是否具有图标。这第二个请求导致脚本执行两次。