how to solve nan error in javascript

Solve the PHPheadersalreadysent error this article is the answer to a question on stackoverflow. The answer focuses on the ideas of other answers and summarizes them, in the future, if you encounter a "headers already sent" error, you can directly troubleshoot it one by one, or simply avoid such problems in code and design. No output before sending the header The

is the name of the callback function. That is to say, due to this wonderful feature of IE8 (similar to IE7), JQuery cannot choose the "silent failure" policy in the case of "abnormal errors" such as network failure, so we can benefit from this and get the opportunity to handle errors. For example, in this case, the "xxxx was not called" dialog box is displayed. SolutionIn case of an "abnormal error", all JSONP of JQuery except IE7 and 8 will be "sile

After wordpress is migrated from apache to nginx, it cannot be opened after the database configuration is correct. Check the http status and the result returns 500, as shown in the figure below:A similar error occurs when the. htaccess configuration in apache is incorrect. The following error occurs:Location /{If (-f $ request_filename/index.html ){Rewrite (. *) $1/index.html break; } If (-f $ request_filen

Solve the error reported by UglifyJs during iview packaging, iviewuglifyjs The run time is OK when npm run dev is used, but iview reports an error when npm run build is packaged, As follows: The reason is that es6 syntax is used in iview, but uglifyJs does not support it. Open the build/webpack. prod. conf. js file and you can see // UglifyJs do not support ES6+

Variables in PHP do not need to be declared with Var, but it is not a problem to use VAR when a variable is a member variable of a class.In fact, this is a very easy problem to solve. In my opinion, familiar, hehe, recently learned JavaScript has learned to use VAR declaration variables. In fact, in PHP does not need to use VAR declaration, but when a variable as a member of a class variable, the use of Var

In the past two days, when using Jquery to retrieve data across domains, I often encounter the invalidlabel error, which is very depressing. The json value sent back from the server is always not obtained. Generally, the two cross-domain methods are used: $. ajax and $. finally, take a closer look at the json official documentation and find the following section: JSON data is a structured data that can be easily parsed using

　　Console.log (0.1+0.2===0.3)// true or false??In normal mathematical logic, the logic of 0.1+0.2=0.3 is correct, but in JavaScript 0.1+0.2! ==0.3, what is this for? This question is also occasionally used as a face test to examine the interviewer'sThe degree to which JavaScript values are understood.Binary floating-point numbers 0.1 and 0.2 in JavaScript are

In a recent web project, javascript cross-origin access was encountered to implement the bookmark function. At first, many solutions searched on google were not suitable for me. I only saw the hope of solving the remote loading javascript method mentioned in an article. However, it is a pity that the author did not use examples to describe it in detail, so I had to explore for a while to

This is what I looked for in the Internet, take the remote file size example. If the domain name is normal, the file size is returned. If the domain name is normal and the file does not exist, it returns false. Now the problem arises, if the domain name is not normal, like the above address, the domain name cannot be resolved, that is, inaccessible. The error message will be output at this time. Php_network_getaddresses:getaddrinfo failed: Do not

displayed in the lower left corner.) The Password Logon Name is correct but cannot be logged in. The uploaded Avatar and photo cannot be saved. For example, you cannot write comments, write articles, write comments, and post comments. ("webpage error" or "javascript" is displayed in the lower left corner.) The Password Logon Name is correct but cannot be logged in. The uploaded Avatar and photo cannot be s

small mistakes in JavaScript-------common error Four: comparison operatorsone of the more convenient parts of JavaScript is the ability to force each result variable in a comparison operation into a Boolean type. But on the other hand, sometimes it can bring us a lot of inconvenience, and here are some examples of code that have been bothering many programmers:Co

From nine JavaScript gotchas, here are nine pitfalls that JavaScript can easily make mistakes.Although not a very sophisticated technical problem, but note that will make your programming easier, that is, the so-called making life easier. Some of the traps will be mixed with some commentary. 1, the last comma As with this code, note the last comma, which should be a good linguistic point (as Python's Dicti

: If you need to introduce external Js, You need to refresh it to execute]Essentially, this is the JavaScript scope issue. If you see it, you will find that there are more than one solution.3. Identify thievesDo not use variable names with the same HTML id in JavaScript. The following code: [Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]IE will report an

introduce external JS, You need to refresh it to execute] Essentially, this is the Javascript scope issue. If you see it, you will find that there are more than one solution. 3. Identify thievesDo not use variable names with the same html id in JavaScript. The following code: [Ctrl + A select all Note: If you need to introduce external JS, You need to refresh it to execute] IE will report an undefin

In the project before the teacher gave us a package of a JS file, to solve the loss of precision in the calculation of some functions, direct reference to the JS file can be used.egvar NumA = 0.1;var NumB = 0.2;Alert (NumA + NumB);Results occurred: 0.1 + 0.2 = 0.30000000000000004Why this problem occurs: the computer reads the binary, not the decimal, is the program in the conversion time lost precision.To resolve the problem code: //The division fu

numbers here are the elements in the array; Data type conversions and Nan: Nan = = Nan: The return is a false parseint (' 123abc '): Return is 123 parseint (' abc123 '): Nan is returned Number (' 123abc '): Nan is returned Number

Landlord now in self-study boostrap, met a beginner may encounter problems. Reported this error Bootstrap ' s JavaScript requires jQueryThe prompt is the error on line 6 . However, the landlord found that the 6th line is a link. the name of the link is not wrong . Later, the landlord only found that the order of the problem.Workaround: 1, the file introduction o

This article mainly introduces how to solve the problem of communication between the parent page and the iframe page through pseudo-Protocol. For more information, see the operations on the parent page and the iframe page. For example: The content in this iframe is written in js. As shown in the following code: var iframe = document.getElementById("iframe"), doc = iframe.contentWindow.document;doc.open();doc.write("---------something------");doc.c

This article mainly introduces how to solve the problem of communication between the parent page and the iframe page through pseudo-protocol. For more information, see the operations on the parent page and the iframe page. for example: The content in this iframe is written in js. As shown in the following code: var iframe = document.getElementById("iframe"), doc = iframe.contentWindow.document;doc.open();doc.write("---------something------");doc.c

Reversesort (values) { if (values instanceof Array) { Values.sort (); Values.reverse (); } } "Communication Error" With the advent of Ajax programming, it has become commonplace for Web applications to dynamically load information or functionality within their lifecycle. However, any communication between JavaScript and the server is likely to produce an