Question

我需要将一些值传递给Javascript中的其他函数。我从另一个PHP文件中获取了值，但我无法将其传递给任何其他Javascript函数。在FOR LOOP之后，SUCCESS中没有任何工作。需要帮助？

url1 = 'http://localhost:81/Dashboard/admin/inc/dashboard.php';
$.ajax({
    url: url1,
    type: "POST",
    dataType: "json",
    success: function(data)
    {
        for(var i = 0; i <= 11; i++) 
        {
            Month = data[i].Month;
            Sales = data[i].Sales;
            if (i == 0) global_ij = "[" + Month + "," + Sales + "]";
            else global_ij = global_ij + "," + "[" + Month + "," + Sales + "]";
        }
        alert ("hello"); // this alert is also not working
    }
});

Answer 1

那是因为您正在执行异步 AJAX操作。换句话说，您正在进行的变量Month，Sale，global_ij的分配仅在该特定success函数中可用＆＃39 ;范围而不是在之外。

一种解决方法是 将async: false添加到您的AJAX调用 ，这会强制它脱离异步行为，因此允许您分配值对于所有剩余代码块可用的变量：

$.ajax({
url: url1,
async: false,
type: "POST",
dataType: "json",
success: function(data)
{
    for(var i = 0; i <= 11; i++) 
    {
        Month = data[i].Month;
        Sales = data[i].Sales;
        if (i == 0) global_ij = "[" + Month + "," + Sales + "]";
        else global_ij = global_ij + "," + "[" + Month + "," + Sales + "]";
    }
}
});

jQuery的AJAX调用返回promise个对象，这些对象强制执行.done()，.fail()等方法。

另一方面，您还可以从AJAX调用中获取 promise （您可以在Javascript代码中的任何位置传递）以及当promise 已解决时调用它的.done()处理程序。

var promise = $.ajax({/* settings */});

/* --- */

// promise passed to some other block of code

promise.done(function(){
    //execute the block of code after the promise was resolved
});

Read more about this here

Answer 2

看起来你的php正在返回8个元素，并且在你的成功方法中你的循环迭代超过11个项目，导致错误。

我将成功函数分开并尝试使用您发布的数据并用data.length替换循环中的11。看看下面的代码：

http://codepen.io/anon/pen/OyXzGb?editors=011

请注意我添加了

var Month;

var Sales;

将这些临时变量保留在函数范围内。

您可能需要检查数据以查看它是否是正确的数组，以捕获错误。在这一行之前：

for（var i = 0; i＆lt; data.length ; i ++）

最终输出和尝试的东西：

var global_ij="";
function processData(data) {
    var Month;
    var Sales;
    for(var i = 0; i < data.length; i++) 
    {
        Month = data[i].Month;
        Sales = data[i].Sales;
        if (i == 0) global_ij = "[" + Month + "," + Sales + "]";
        else global_ij = global_ij + "," + "[" + Month + "," + Sales + "]";
        console.log(global_ij);
    }
    return global_ij;
}

首先试用这个没有ajax的函数：

过程数据（[{＆＃34;月＆＃34;：＆＃34; 1＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34 ;：＆＃34; 19746.81＆＃34;}，
{＆＃34;月＆＃34;：＆＃34; 2＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34;：＆＃34; 17902.26＆＃34;}，{＆＃34;月＆＃34;：＆＃34; 3＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃ 34;：＆＃34; 19223.84＆＃34;}，{＆＃34;月＆＃34;：＆＃34; 4＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34; ＆＃34;销售＆＃34;：＆＃34; 18840.88＆＃34;}，{＆＃34;月＆＃34;：＆＃34; 5＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34;：＆＃34; 19889.97＆＃34;}，{＆＃34;月＆＃34;：＆＃34; 6＆＃34;＆＃34 ;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34;：＆＃34; 18509.85＆＃34;}，{＆＃34;月＆＃34;：＆＃34; 7＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34;：＆＃34; 1886.81＆＃34;}，{＆＃34;月＆＃34 ;：＆＃34; 8＆＃34;＆＃34;年份＆＃34;：＆＃34; 2015＆＃34;＆＃34;销售＆＃34;：＆＃34; 1740.34＆＃34;}]） ;

您可能想要使用.done()

Answer 3

修改代码以在循环外声明gloabla_ij变量。有点像下面..

var global_ij='0';
url1 = 'http://localhost:81/Dashboard/admin/inc/dashboard.php';
$.ajax({
    url: url1,
    type: "POST",
    dataType: "json",
    success: function(data)
    {
        for(var i = 0; i <= 11; i++) 
        {
            Month = data[i].Month;
            Sales = data[i].Sales;
            if (i == 0) global_ij = "[" + Month + "," + Sales + "]";
            else global_ij = global_ij + "," + "[" + Month + "," + Sales + "]";
        }
    }
});

Answer 4

如果在文件顶部声明var，则文件中的任何函数都可以使用它：

var global_ij; // declare variable in global scope of module/file

$.ajax({
    url: 'http://localhost:81/Dashboard/admin/inc/dashboard.php',
    type: "POST",
    dataType: "json",
    success: function(data) {

        var i, month, sales, len = data.length;

        for(i=0; i<=len; i++) {

            month = data[i].Month;
            sales = data[i].Sales;

            if (i===0) global_ij = "[" + month + "," + sales + "]";
            else global_ij = global_ij + "," + "[" + month + "," + sales + "]";
        }

        doSomething(); // can now call function after loop finished
    }
});

func doSomething() {
    // global_ij is now populated
}

Answer 5

PHP文件的响应是：

[
    {"Month":"1","Year":"2015","Sales":"19746.81"},  // 1
    {"Month":"2","Year":"2015","Sale‌s":"17902.26"},  // 2
    {"Month":"3","Year":"2015","Sales":"19223.84"},  // 3
    {"Month":"4","Year"‌:"2015","Sales":"18840.88"},  // 4
    {"Month":"5","Year":"2015","Sales":"19889.97"},  // 5
    {"Mont‌h":"6","Year":"2015","Sales":"18509.85"},  // 6
    {"Month":"7","Year":"2015","Sales":"1886‌.81"},   // 7
    {"Month":"8","Year":"2015","Sales":"1740.34"}    // 8
]

然而你正在循环

for(var i = 0; i <= 11; i++)

因此当i >= 8时，data[i].Month会抛出＆＃34;数据[i]未定义＆＃34;错误。

只需使用.length属性：

for(var i = 0; i < data.length; i++)

Example Fiddle

JavaScript jquery.ajax成功后循环无效

5 个答案: