JavaScript：從PHP腳本中提取信息

Question

我遇到的問題是我不確定正確的代碼以便開始從我在較早版本的函數中解析的PHP腳本中提取。 首先這是代碼

function getExibitions()
{
myExhibitionsView = document.getElementById('exhibitioncontent');
option = document.createElement('ul');

 for (var i = 0; i < json.length; i++) {
      option.id = 'exhibitionsAll';
       listCheck = document.createElement('src');
       listCheck.id = "<img src = " + "./images/" + json.exhibits[i].exhibit_image;
      myExhibitionsView.appendChild(option);
      option.appendChild(listCheck);   
       //= json.states[i].image;  
      }

}

我認為這個問題是在json.something.length之后必須有一些作為遍歷數據的方法。

這是PHP腳本：

<?php
    $exhibitionsarray = array(
            array("exhibition_id" => "1", "exhibition_title" => "New York, New York", "exhibition_subject" => "New York", "ticket_price" => "10",
                "exhibits" => array(
                    array("exhibit_id" => "3", "exhibit_title" => "Brooklyn Bridge from City Hall Park", "exhibit_description" => "New York, June 2005", "exhibit_image" => "brooklynbridge.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "6", "exhibit_title" => "Central Park, New York", "exhibit_description" => "New York, June 2005", "exhibit_image" => "centralpark.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "7", "exhibit_title" => "Chrysler Building at night, New York", "exhibit_description" => "New York, July 2001", "exhibit_image" => "chrysler_building.jpg", "photographer" => "MLG")
                ),
                "locations" => array(
                    array("location_id" => "1", "location_name" => "Kelvingrove Art Gallery and Museum", "location_postcode" => "G3 8AG"),
                    array("location_id" => "3", "location_name" => "Walker Art Gallery", "location_postcode" => "L3 8EL"),
                    array("location_id" => "5", "location_name" => "Tate Modern", "location_postcode" => "SE1 9TG")
                )
            ),
            array("exhibition_id" => "2", "exhibition_title" => "Spanish Cities", "exhibition_subject" => "Spain", "ticket_price" => "15",
                "exhibits" => array(
                    array("exhibit_id" => "9", "exhibit_title" => "Eiffel Bridge, Girona", "exhibit_description" => "Girona, March 2008", "exhibit_image" => "eiffel_bridge.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "13", "exhibit_title" => "Plaza Mayor, Madrid", "exhibit_description" => "Madrid, June 2010", "exhibit_image" => "plazamayor.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "14", "exhibit_title" => "Puppy (Day)", "exhibit_description" => "Bilbao, September 2006 - Puppy in daylight", "exhibit_image" => "puppy_day.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "15", "exhibit_title" => "Puppy (Night)", "exhibit_description" => "Bilbao, March 2011 - Puppy at night", "exhibit_image" => "puppy_night.jpg", "photographer" => "LPK")                                                                      
                ),
                "locations" => array(
                    array("location_id" => "2", "location_name" => "Scottish National Gallery", "location_postcode" => "EH2 2EL")
                )                                               
            ),
            array("exhibition_id" => "3", "exhibition_title" => "A Glasgow Viewpoint", "exhibition_subject" => "Glasgow", "ticket_price" => "5",
                "exhibits" => array(
                    array("exhibit_id" => "2", "exhibit_title" => "Bothwell Castle", "exhibit_description" => "Bothwell, April 2011", "exhibit_image" => "bothwell_castle.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "10", "exhibit_title" => "Hampden Park", "exhibit_description" => "Glasgow, June 2007 - SQA Event", "exhibit_image" => "hampden.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "11", "exhibit_title" => "Hogganfield Loch, Glasgow, Winter", "exhibit_description" => "Glasgow, January 2010", "exhibit_image" => "hogganfield_loch.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "16", "exhibit_title" => "Ramblas", "exhibit_description" => "Barcelona, July 1999 - Ramblas (Two Old Friends from Glasgow)", "exhibit_image" => "ramblas.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "17", "exhibit_title" => "River Clyde at Bothwell", "exhibit_description" => "Bothwell, April 2011 - River Clyde from Bothwell", "exhibit_image" => "river_clyde.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "18", "exhibit_title" => "River Kelvin", "exhibit_description" => "Glasgow, July 2011", "exhibit_image" => "river_kelvin.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "21", "exhibit_title" => "University Avenue", "exhibit_description" => "Glasgow, July 2011", "exhibit_image" => "university_avenue.jpg", "photographer" => "LPK")                                                                     
                ),
                "locations" => array(
                    array("location_id" => "1", "location_name" => "Kelvingrove Art Gallery and Museum", "location_postcode" => "G3 8AG"),
                    array("location_id" => "2", "location_name" => "Scottish National Gallery", "location_postcode" => "EH2 2EL"),
                    array("location_id" => "3", "location_name" => "Walker Art Gallery", "location_postcode" => "L3 8EL"),
                    array("location_id" => "4", "location_name" => "The Lowry", "location_postcode" => "M50 3AZ"),
                    array("location_id" => "5", "location_name" => "Tate Modern", "location_postcode" => "SE1 9TG")
                )                                                   
            ),
            array("exhibition_id" => "4", "exhibition_title" => "Some Churches", "exhibition_subject" => "Religious Architecture", "ticket_price" => "5",
                "exhibits" => array(
                    array("exhibit_id" => "1", "exhibit_title" => "Big Ben", "exhibit_description" => "London, September 2011", "exhibit_image" => "big_ben.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "12", "exhibit_title" => "Louvre, Paris", "exhibit_description" => "Paris, June 1998", "exhibit_image" => "louvre.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "19", "exhibit_title" => "Sagrada Familia - Honeymoon", "exhibit_description" => "Barcelona, June 1997 - Honeymoon", "exhibit_image" => "sagrada.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "20", "exhibit_title" => "Mormon Temple", "exhibit_description" => "Salt Lake City, July 2005", "exhibit_image" => "salt_lake.jpg", "photographer" => "MLG")                                                                      
                ),
                "locations" => array(
                    array("location_id" => "1", "location_name" => "Kelvingrove Art Gallery and Museum", "location_postcode" => "G3 8AG"),
                    array("location_id" => "2", "location_name" => "Scottish National Gallery", "location_postcode" => "EH2 2EL")
                )                                                   
            ),
            array("exhibition_id" => "5", "exhibition_title" => "Barcelona Highlights", "exhibition_subject" => "Barcelona", "ticket_price" => "15",
                "exhibits" => array(
                    array("exhibit_id" => "4", "exhibit_title" => "Martin at Camp Nou, Honeymoon", "exhibit_description" => "Barcelona, June 1997 - Honeymoon", "exhibit_image" => "campnou.jpg", "photographer" => "LPK"),
                    array("exhibit_id" => "5", "exhibit_title" => "Placa de Catalunya, Barcelona - Honeymoon", "exhibit_description" => "Barcelona, June 1997 - Honeymoon", "exhibit_image" => "catalunya.jpg", "photographer" => "MLG")
                ),
                "locations" => array(
                    array("location_id" => "3", "location_name" => "Walker Art Gallery", "location_postcode" => "L3 8EL"),
                    array("location_id" => "4", "location_name" => "The Lowry", "location_postcode" => "M50 3AZ"),
                    array("location_id" => "5", "location_name" => "Tate Modern", "location_postcode" => "SE1 9TG")
                )                                                   
            ),
            array("exhibition_id" => "6", "exhibition_title" => "Martin’s Pictures", "exhibition_subject" => "Martin", "ticket_price" => "5",
                "exhibits" => array(
                    array("exhibit_id" => "8", "exhibit_title" => "David Crosby at David Gilmour gig", "exhibit_description" => "Glasgow, May 2006", "exhibit_image" => "davidcrosby.jpg", "photographer" => "MLG"),
                    array("exhibit_id" => "22", "exhibit_title" => "Wolves", "exhibit_description" => "Yellowstone Park, October 2004", "exhibit_image" => "wolves.jpg", "photographer" => "MLG")
                ),
                "locations" => array(
                    array("location_id" => "1", "location_name" => "Kelvingrove Art Gallery and Museum", "location_postcode" => "G3 8AG"),
                    array("location_id" => "3", "location_name" => "Walker Art Gallery", "location_postcode" => "L3 8EL"),
                    array("location_id" => "4", "location_name" => "The Lowry", "location_postcode" => "M50 3AZ"),
                    array("location_id" => "5", "location_name" => "Tate Modern", "location_postcode" => "SE1 9TG")
                )
            )               
    );
    echo json_encode($exhibitionsarray);
?>

我確定json.exhibits.length可以解決問題， json.exhibits.length會導致一些錯誤，例如json和length都未定義，所以我知道我的錯誤在這里。 我做過類似的代碼，但遵循相同的修復程序卻沒有成功。

編輯：json解析

function jsonAll()
{
    console.log("in function!");
    url = "exhibitions.php";
    xmlhttp.onreadystatechange = function() {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        console.log("the connection is complete");
        json = JSON.parse(xmlhttp.responseText);
        console.log(json);
        getExibitions();
}
    }

    xmlhttp.open("GET", url, true);
xmlhttp.send();
}

Answer 1

如果您想獲取所有展品，則需要兩個循環：

for (var i = 0; i < json.length; i++) {
    for (var j = 0; j < json[i].exhibits.length; j++) {
        listCheck = document.createElement('src');
        listCheck.id = "<img src = " + "./images/" + json[i].exhibits[j].exhibit_image;
        myExhibitionsView.appendChild(option);
        option.appendChild(listCheck);
    }
}

Answer 2

您的問題有點難以理解，但是我認為問題是您沒有正確地遍歷JSON數據。

var exhibition = json[i]; var exhibit = json[i].exhibits[j];

因此，您可能需要第二個for循環