jQuery JavaScript lastIndexOf()
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JavaScript lastIndexOf()
提问by paradise_lost
In C# I can do this
在 C# 中，我可以做到这一点
string ID = "ContentPlaceHolderDefault_MainSiteSectionArea_MyPagePlaceHolder_Item4_FavoritAmusementCalender_6_deleteRight_2"; ??
ID = ID.Substring(ID.LastIndexOf("_") + 1);?
to return the last int 2
返回最后一个 int 2
How can I most easily do this in jQuery/JavaScript
我怎样才能最容易地在 jQuery/JavaScript 中做到这一点
The id is created dynamic and can for now be up to 3 digit.
id 是动态创建的，现在最多可以是 3 位数字。
Thanks in advance.
提前致谢。
回答by sgeddes
You were close -- just case sensitive:
你很接近——只是区分大小写：
ID = ID.substring(ID.lastIndexOf("_") + 1);
回答by paxdiablo
JavaScript also has a lastIndexOf()method, see here. You can therefore use:
JavaScript 也有一个lastIndexOf()方法，见这里。因此，您可以使用：
var str1 = "Blah, blah, blah Calender_6_deleteRight_272";
var str2 = str1.substr (str1.lastIndexOf ("_") + 1);
This gives you 272.
这给你272。
Keep in mind that, if the string doesn'tcontain an underscore, you'll get the original string back in its entirety. That may or may not be desired in your specific case - you can check the result of the lastIndexOf()call against -1to detect this.
请记住，如果字符串不包含下划线，您将恢复完整的原始字符串。在您的特定情况下可能需要也可能不需要 - 您可以检查lastIndexOf()调用的结果-1来检测这一点。
回答by s3m3n
You should do this with:
你应该这样做：
function get_last_part(str){
var split = str.split('_');
return split[split.length-1];
}
console.log(get_last_part("ContentPlaceHolderDefault_MainSiteSectionArea_MyPagePlaceHolder_Item4_FavoritAmusementCalender_6_deleteRight_2")); // this will write "2" in console
In this way you will get always result and you don't need to concern about out of index problems. This will return always last part of your string, if it doesn't have _you will get first part of it.
通过这种方式，您将始终获得结果，而无需担心索引不足的问题。这将始终返回字符串的最后一部分，如果没有，_您将获得它的第一部分。
console.log(get_last_part("Content")); // will write "Content" into console
回答by Niet the Dark Absol
Have you tried str.substr(-1)?
你试过str.substr(-1)吗？
