Check Error Javascript
Contents |
About unsafe line breaks About potential typos in logical operators javascript error handling When code is not in strict mode When new is used for side-effects Assume Browser NodeJS jQuery Development (console, etc.) New JavaScript features (ES6) Mozilla JavaScript extensions Older environments (ES3) Metrics version 2.9.3 About Documentation Install Contribute Blog
statementmultiple varssingle quote stringsthiswhitespace messNumber...Maximum line lengthMaximum warningsGlobal variables...
the new WordPress Code Reference! Using Your Browser to Diagnose JavaScript Errors If you're experiencing issues with your interactive functionality this may be due to JavaScript errors or conflicts. For example, your flyout menus https://codex.wordpress.org/Using_Your_Browser_to_Diagnose_JavaScript_Errors may be broken, your metaboxes don't drag, or your add media buttons aren't working. In order to formulate your support request it helps the team to know what the JavaScript error is. http://eloquentjavascript.net/1st_edition/chapter5.html This guide will show you how to diagnose JavaScript issues in different browsers. Contents 1 Step 1: Try Another Browser 2 Step 2: Enable SCRIPT_DEBUG 3 Step 3: Diagnosis 3.1 Firefox javascript error 3.2 Internet Explorer 3.3 Chrome 3.4 Safari 3.5 Opera 4 Step 4: Reporting Step 1: Try Another Browser To make sure that this is a JavaScript error, and not a browser error, first of all try opening your site in another browser. if the site is not having the same issue in the new browser you know that the error is browser specific if javascript error check the site is having the same error it is not an error that is specific to one browser Make note of any browsers you are experiencing the error in. You can use this information when you are making a support request. Step 2: Enable SCRIPT_DEBUG You need to turn on script debugging. Open wp-config.php and add the following line before "That's all, stop editing! Happy blogging". define('SCRIPT_DEBUG', true); Check to see if you are still having an issue. Issue is fixed - turn off script debugging and report the issue on the support forum, telling the volunteers that you turned on script debugging and it solved the problem. Issue persists - proceed to Step 3. Step 3: Diagnosis Now that you know which browsers you are experiencing issues in you can start to diagnose the issue. Firefox 1. Open the Console Go to the screen where you are experiencing the error. In Firefox, navigate to Tools > Web Developer > Error Console or press Ctrl + Shift + J. 2. Identify the Error The error console will open. If you don't see any errors try reloading the page.
as expected is a good start. Making your programs behave properly when encountering unexpected conditions is where it really gets challenging. ¶ The problematic situations that a program can encounter fall into two categories: Programmer mistakes and genuine problems. If someone forgets to pass a required argument to a function, that is an example of the first kind of problem. On the other hand, if a program asks the user to enter a name and it gets back an empty string, that is something the programmer can not prevent. ¶ In general, one deals with programmer errors by finding and fixing them, and with genuine errors by having the code check for them and perform some suitable action to remedy them (for example, asking for the name again), or at least fail in a well-defined and clean way. ¶ It is important to decide into which of these categories a certain problem falls. For example, consider our old power function:function power(base, exponent) { var result = 1; for (var count = 0; count < exponent; count++) result *= base; return result; } ¶ When some geek tries to call power("Rabbit", 4), that is quite obviously a programmer error, but how about power(9, 0.5)? The function can not handle fractional exponents, but, mathematically speaking, raising a number to the halfth power is perfectly reasonable (Math.pow can handle it). In situations where it is not entirely clear what kind of input a function accepts, it is often a good idea to explicitly state the kind of arguments that are acceptable in a comment. ¶ If a function encounters a problem that it can not solve itself, what should it do? In chapter 4 we wrote the function between:function between(string, start, end) { var startAt = string.indexOf(start) + start.length; var endAt = string.indexOf(end, startAt); return string.slice(startAt, endAt); } ¶ If the given start and end do not occur in the string, indexOf will return -1 and this version of between will return a lot of nonsense: between("Your mother!", "{-", "-}") returns "our mother". ¶ When the program is running, an