“IF ELSE”Javascript 不工作
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"IF ELSE" Javascript not working
提问by user1708580
A) I have a first function which works very well :
A）我有第一个功能很好用：
if(onlyUs == '1' && idUser == '0'){
obj.after(jQuery('<div />').css({'clear':'both'}).addClass('kklike-msg').text('Only registered users can vote.'));
setTimeout(function(){
jQuery('.kklike-msg').fadeOut('normal');
},3000);
return false;
}
B) So I thought I could do the following thing :
B）所以我想我可以做以下事情：
if(idUser == '0'){
if(action == 'like'){
var ajaxAction = 'add_like';
}else{
var ajaxAction = 'remove_like';
}
}else{
if(action == 'like'){
var ajaxAction = 'add_like';
window.open('http://mywebsite.com/like')
}else{
var ajaxAction = 'remove_like';
window.open('http://mywebsite.com/remove')
}
}
C) Knowing that the original function is simply (works well):
C) 知道原始函数很简单（运行良好）：
if(action == 'like'){
var ajaxAction = 'add_like';
}else{
var ajaxAction = 'remove_like';
}
But B) is not working.In both condition (Login or not), the new window is going to open. Do you have a solution ?
但是 B) 不起作用。在两种情况下（登录与否），新窗口都会打开。你有解决方案吗 ？
回答by Dan Herbert
Without knowing the typeof idUser, it is difficult to tell what the problem is, but the most likely culprit is the use of ==for comparison instead of ===. JavaScript will convert the variables being compared into similar types when using ==, which can cause some very unpredictable results in your case.
如果不知道类型的idUser，它是很难说是什么问题，但最有可能的罪魁祸首是利用==比较替代===。使用 时，JavaScript 会将要比较的变量转换为类似的类型==，这可能会在您的情况下导致一些非常不可预测的结果。
I recommend writing your code like the following. If this still does not work as you expected, you should investigate what the value of idUseractually is. It may not be a stringwhich would be the cause of your problem.
我建议您编写如下代码。如果这仍然不能按您的预期工作，您应该调查实际的值idUser是什么。它可能不是string导致您问题的原因。
if (idUser === '0') {
if(action === 'like') {
var ajaxAction = 'add_like';
} else {
var ajaxAction = 'remove_like';
}
} else {
if (action === 'like') {
var ajaxAction = 'add_like';
window.open('http://mywebsite.com/like');
} else {
var ajaxAction = 'remove_like';
window.open('http://mywebsite.com/remove');
}
}
For a very simple example of why you should use ===, see this blog post:
有关为什么应该使用 的一个非常简单的示例===，请参阅此博客文章：
http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html
http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html
