全球与Javascript中的局部变量 [英] Global & Local variables in Javascript

问题描述

我有一个变量和两个函数.两者都使用该变量.第一个函数是每次使用变量值时(全局)更改它.这是我想要的，但它对我不起作用.

I have one variable and two functions . The variable is used by both. and the first function is changing the variable value (globally) each time it's used by it . This is what I want but it is not working with me .

x = 1;

function f1()
{
  x = x + 1;
  // use x 
} 

function f2()
{
  // use x
}

我读过其他线程，但是x始终为1，这非常令人沮丧:|

I've read other threads but x is always 1 which is very frustrating :|

添加:实际代码

<script type="text/javascript">

function S4() {
return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
}

function guid() {
return (S4() + S4() + ";" + S4() + ";" + S4() + ";" + S4() + ";" + S4() + S4() + S4());
}

P = '';

function Save() {
P = guid();
$('#btnBrowse').uploadifyUpload();
}

$(document).ready(function () {


            $('#txtText').elastic();

            $('#btnBrowse').uploadify({
                'uploader': '../uploadify.swf',
                'script': '../uploadify.ashx',
                'cancelImg': '/uploadify/cancel.png',
                'folder': '../images/Albums/',
                'multi': true,
                'fileDesc': 'Web Image Files (.JPG, .GIF, .PNG)',
                'fileExt': '*.jpg;*.gif;*.png',
                'scriptData': { 'Album_ID': P },
                'buttonText': 'Upload Images'
            });

});

</script>

所以变量是P.并由jquery函数(uploadify)使用.每次我执行 保存功能我希望我得到变量P的新值.但是总是一样的?

so the variable is P . and it is used by jquery function (uploadify) . each time I excute Save function I expect I get a new value for variable P . But is always the same ??

推荐答案

问题是执行代码的时间时间. uplodify选项是在页面加载上设置的(包括P在页面加载时传递)，并且由于P是字符串，因此以后(通过save())更改P不会更改您传递的值.

The problem is the time when you execute the code. The uplodify options are set on page load (which includes that P is passed on page load) and as P is a string, changing P later (through save()) will not change the value you passed.

您可以通过传递对对象的引用作为选项来解决此问题，而不是字符串 无效.

该插件提供了 uploadifySettings ^[docs] 方法来更改uploadify实例的设置.使用它来更新scriptData设置:

The plugin provides a uploadifySettings ^[docs] method to change the settings of an uploadify instance. Use it to update the scriptData settings:

function Save() {
    $('#btnBrowse').uploadifySettings('scriptData', {'Album_ID' : guid()}, true);
    $('#btnBrowse').uploadifyUpload();
}

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