The from form is used to write the mobile terminal page using the vant framework, but the error is reported in the from verification 
Solution:
Each field of the form must have the :Rules attribute, otherwise the above error will be reported.
That is, add the :Rules validation attribute to each van field form item, even if the current form item does not perform any validation
This is because Safari browser does not support regular expression zero assertion in two// formats:<= , ?<!
Solution:
Use constructor instead of// format
let reg = /ab?<=cd/
Change to
let reg = new RegExp('ab(?<=cd)')Semi in eslint is to check whether the semicolon is wrong. No trailing spaces is the absence of spaces in the code 
Open. Eslintrc.js in the project and add the following code in the rules to solve the above problems. Just add the first and second lines of code in the box. Some are added to the problems later. It is recommended to add them because they are useful later.
'space-before-function-paren': 0,
'semi': 'off',
'quotes' : 'off',
'comma-dangle' : 'off',
'vue/comment-directive': 'off'
Eslint requires strict code format. Sometimes errors will occur when there are fewer or more spaces. It is recommended to replace the extensions in. Eslintrc.js in the project ‘@ Vue/standard ‘is commented out. This will reduce many subsequent format problems.
Solve the error: cannot find module ‘@ Vue/cli shared utils‘
Solution: 1. Delete node_modules Folder 2. Run NPM install3. Finally, restart and yarn serve
Solution:
1. Delete node_Modules folder
2. Run NPM install
3. Finally, restart, yarn serve
Error: Request failed with status code 401
Error:
// Access to personal information
export const getUserInfoAPI = () => {
return request({
url: '/v1_0/user/profile',
method: 'GET',
Headers: {
Authorization: `Bearer ${getToken()}`
}
})
}
Correct practice
// Access to personal information
export const getUserInfoAPI = () => {
return request({
url: '/v1_0/user/profile',
method: 'GET',
headers: {
Authorization: `Bearer ${getToken()}`
}
})
}
In the process of writing request headers, the use of headers did not notice the case problem!!!
Sometimes when typing JS code, you will often encounter such errors:
This is due to careless typing of code, resulting in grammatical format errors.
If the object literal is used to define the object, the relationship between the attribute name and the attribute value:
<script>
var province = [{
id: 1002,
name: 'Heibei',
city: [{
id: 1,
name= 'Shijiazhuang' // use object literals to define objects with attribute names separated from attribute values by:.
},
{
id: 2,
name: 'Handan'
}
]
}];
</script>Grammar norms are very important. Try not to make mistakes that can be avoided.
After updating the version of eslint, there is an error of typeerror: this.cliengine is not a constructor.
Solution:
1. Click Details — “find the following red path –” open the file with editing
2. Find the following clip
Add the content in the red box. Cliengine, save and reopen the project
Many students have encountered this problem when writing JS code: 
Cannot set properties of null (setting ‘innerHTML’). This error means that the null property “innerHTML” cannot be read, which means that the place where you want to insert the written HTML code cannot be found.
Solution: put the script of the read part of the DOM behind the body. Or add window.onload in the script tag and execute this part of the code after the page is loaded.
Reason: when the browser loads the HTML document, it will parse the HTML document into a tree structure called DOM tree. The code is executed from top to bottom. When the innerHTML line of code is executed, it does not load into the following DOM structure, and an error will be reported that the HTML cannot be read.
Example:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
function showTime() {
var today = new Date;
var year = today.getFullYear();
var month = checkNum(today.getMonth() + 1);
var data = checkNum(today.getDate());
var hour = today.getHours();
var minute = checkNum(today.getMinutes());
var second = checkNum(today.getSeconds());
var day = today.getDay();
var a = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
var tip = 'PM'
if (hour > 12) {
hour -= 12;
tip = 'AM'
}
var time = year + 'Year' + month + 'Month' + data + 'date' + ' ' + tip + ' ' + hour + ':' + minute + ':' +
second + ' ' + a[day];
document.getElementById('time').innerHTML = time;
}
function checkNum(num) {
if (num < 10) {
return '0' + num;
}
return num;
}
setInterval(showTime, 1000);
</script>
</head>
<body>
<div id="time"> </div>
</body>
</html>Solution: will setInterval(showTime, 1000); Put this line of code after the body:
<body>
<div id="time"> </div>
</body>
<script>
setInterval(showTime, 1000);
</script>
</html>Or add window.onload to the original script tag
window.onload = function () {
setInterval(showTime, 1000);
}
</script>This can be solved perfectly!
Several error messages were encountered when learning Vue project was packaged
★ Extra semicolon
The first is that there is an additional semicolon. The error query found that main.js does have a semicolon. After we deleted it, the error disappeared
★ Expected indentation of 2 spaces but found 4
The second one is “expected to indent 2 spaces, but found 4”. After Baidu search, it is found that this is not an error, but a check rule. Find this file in the project and add this configuration. See the figure below
★ Newline required at end of file but not found
The third one is more wonderful. It means that “line breaks are required at the end of the file, but they are not found”. Then we go to the error file, that is, main.js. We can solve the error by typing enter at the end. See the figure below
Adding a blank line here can solve the problem of error reporting
Open the terminal and enter nodemon./index.js. The following error messages appear:
Solution:
After entering the directory where index.js is located
delete node_ Module folder and package lock.json file open the terminal, type NPM clean cache , clear the cache, type NPM I , and type nodemon index. JS for installation dependency
Run nodemon./index.js again
Perfect solution~
To use less, you need to download less and less loader
npm install less less-loader --save-dev
In this way, an error will be reported after running. The reason is that the loader version is too high. Just reduce the version
Uninstall less loader
NPM uninstall less loader
install less loader
NPM install less- [email protected] --save-dev
‘gbk’ codec can’t encode character ‘\u20ac’ in position 62114: illegal multibyte sequence
find this line in the JS files:
e = "a€|",
It should be this symbol that reports an error. How to solve it
with open('./encryp_js/eventid_encryp.js', 'r', encoding='utf-8') as f:
content = f.read()
jsdata = execjs.compile(content)