子串在jquery中不起作用。 [英] Substring is not working in jquery.

问题描述

1。我需要在for循环中创建如下所示的li列表

1. I need to create li list like below in for loop

$('#lstAPIs').append("<li  id='" + list[i].Uuid + "'>" + "<div>" + eventIcon + "</div><div  style='float:left;'><h4 title=" + list[i].UserIdentity + ">" + list[i].UserIdentity.substring(0, 15) + "..." + "</h4><hr style='width:100%;border:1px dotted silver;'/><h5>" + list[i].TransactionName.substring(0, 23) + "..." + "</h5></div></div>" + ' </li>');

如果我给sbustring或substr



i我得到以下错误你能否建议如何解决这个问题。

If i give sbustring or substr

i am getting the below error could you please suggest how to fix this.

Uncaught TypeError: Cannot read property 'substring' of undefined

我的jquery版本是3.1.1版本



我试过的：

My jquery version is 3.1.1 version

What I have tried:

$('#lstAPIs').append("<li  id='" + list[i].Uuid + "'>" + "<div>" + eventIcon + "</div><div  style='float:left;'><h4 title=" + list[i].UserIdentity + ">" + list[i].UserIdentity.substring(0, 15) + "..." + "</h4><hr style='width:100%;border:1px dotted silver;'/><h5>" + list[i].TransactionName.substring(0, 23) + "..." + "</h5></div></div>" + ' </li>');

为此获得以下错误

for this getting the below error
"

Uncaught TypeError: Cannot read property 'substring' of undefined

推荐答案

（'＃lstAPIs'）。append（< li id ='+ list [i] .Uuid +'>+ < div>+ eventIcon +< / div>< div style ='float：left;'>< h4 title =+ list [i] .UserIdentity +>+ list [i ] .UserIdentity.substring（0,15）+...+< / h4>< hr style ='width：100％; border：1px点缀银;'/>< h5>+ list [i] .TransactionName.substring（0,23）+...+< / h5>< / div>< / div>+'< / li>'）;

('#lstAPIs').append("<li id='" + list[i].Uuid + "'>" + "<div>" + eventIcon + "</div><div style='float:left;'><h4 title=" + list[i].UserIdentity + ">" + list[i].UserIdentity.substring(0, 15) + "..." + "</h4><hr style='width:100%;border:1px dotted silver;'/><h5>" + list[i].TransactionName.substring(0, 23) + "..." + "</h5></div></div>" + ' </li>');

如果我给sbustring或substr



i我得到以下错误你能建议如何解决这个问题。

If i give sbustring or substr

i am getting the below error could you please suggest how to fix this.

Uncaught TypeError: Cannot read property 'substring' of undefined

我的jquery版本是3.1.1版本



我尝试过：

My jquery version is 3.1.1 version

What I have tried:

（'＃lstAPIs'）。append（< li id ='+ list [i] .Uuid + '>+< div>+ eventIcon +< / div>< div style ='float：left;'>< h4 title =+ list [i] .UserIdentity +> + list [i] .UserIdentity.substring（0,15）+......+< / h4>< hr style ='width：100％; border：1px dotted silver;'/>< ; h5>+ list [i] .TransactionName.substring（0,23）+...+< / h5>< / div>< / div>+'< / li>' ）;

('#lstAPIs').append("<li id='" + list[i].Uuid + "'>" + "<div>" + eventIcon + "</div><div style='float:left;'><h4 title=" + list[i].UserIdentity + ">" + list[i].UserIdentity.substring(0, 15) + "..." + "</h4><hr style='width:100%;border:1px dotted silver;'/><h5>" + list[i].TransactionName.substring(0, 23) + "..." + "</h5></div></div>" + ' </li>');

为此获得以下错误

for this getting the below error
"

Uncaught TypeError: Cannot read property 'substring' of undefined

我们无法帮助您，原因很简单，我们不知道列表中的内容[i ] 。

我们只能猜测你是否尝试在不是字符串的东西上应用 substring 。 />


有一个工具可以让你看到你的代码在做什么，它的名字是调试器。它也是一个很好的学习工具，因为它向你展示了现实，你可以看到哪种期望与现实相符。

当你不明白你的代码在做什么或为什么它做它做的时候，答案就是答案是调试器。

使用调试器查看代码正在执行的操作。只需设置断点并查看代码执行情况，调试器允许您逐行执行第1行并在执行时检查变量。



调试器 - 维基百科，免费的百科全书 [ ^ ]

JavaScript调试 [ ^ ]

Chrome DevTools  | 网络  |  Google Developers [ ^ ]

调试器在这里向您展示您的代码正在做什么，您的任务是与它应该做什么进行比较。

调试器中没有魔法，它不是'找到错误，它只是帮助你。当代码没有达到预期的效果时，你就会接近一个错误。

We can't help you on this for the simple reason that we have no idea of what is in list[i].
One can only guess that you try to apply substring on something that is not a string.

There is a tool that allow you to see what your code is doing, its name is debugger. It is also a great learning tool because it show you reality and you can see which expectation match reality.
When you don't understand what your code is doing or why it does what it does, the answer is debugger.
Use the debugger to see what your code is doing. Just set a breakpoint and see your code performing, the debugger allow you to execute lines 1 by 1 and to inspect variables as it execute.

Debugger - Wikipedia, the free encyclopedia[^]
JavaScript Debugging[^]
Chrome DevTools  |  Web  |  Google Developers[^]
The debugger is here to show you what your code is doing and your task is to compare with what it should do.
There is no magic in the debugger, it don't find bugs, it just help you to. When the code don't do what is expected, you are close to a bug.

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