Regular, the question mark is still greedy to match the problem. - Codes Helper - Programming Question Answer

Regular, the question mark is still greedy to match the problem.

var str="<iframe frameborder="0" width="640" height="498" src="https://v.qq.com/iframe/player.html?vid=a0678a3ahqx&tiny=0&auto=0" allowfullscreen=""></iframe><iframe frameborder="0" width="640" height="498" src="https://v.qq.com/iframe/player.html?vid=a0678a3ahqx&tiny=0&auto=0" allowfullscreen=""></iframe>"
var result=str.replace(/(<iframe) (.*) (width=\".*?\") (height=\".*?\") (.*)(<.*?iframe>)/g,"$1 $2 width="100%" $5 $6")
console.log(result)

I want to replace width= "640" height= "498" in iframe with width= "100%"
, so I write the above rule and find that if only one iframe in the string is successfully replaced, but if there are two iframe, it will only replace the second iframe.
ask for help, hope that in each iframe, Width= "640" height= "498" becomes width=

online debugging address http://jsbin.com/dumuxewubu/e.

= split line, problem solved =
found that the previous non-greedy matching method was added wrong, should not use (. *)? Write the question mark in parentheses.
use this

.

var result=str.replace(/(<iframe) (.*?) (width=\".*?\") (height=\".*?\") (.*?)(<.*?iframe>)/g,"$1 $2 width="100%" $5 $6")

Javascript javascript-regular

Mar.17,2021

solved, found that the previous non-greedy matching method added wrong, should not use (. *)? Write the question mark in parentheses.
use this

.

,,(.*)? ,

var result=str.replace(/(<iframe) (.*?) (width=\".*?\") (height=\".*?\") (.*?)(<.*?iframe>)/g,"$1 $2 width='100%' $5 $6")

if there are no performance requirements (but it must be much faster than using jquery to insert and modify), you can use cheerio, so you don't have to mess with regularities (and it's safe)

import cheerio from 'cheerio';
var str='<iframe frameborder="0" width="640" height="498" src="https://v.qq.com/iframe/player.html?vid=a0678a3ahqx&tiny=0&auto=0" allowfullscreen=""></iframe><iframe frameborder="0" width="640" height="498" src="https://v.qq.com/iframe/player.html?vid=a0678a3ahqx&tiny=0&auto=0" allowfullscreen=""></iframe>'
var $ = cheerio.load(str, {decodeEntities: false});
$('iframe').attr('width','100%')
console.log($.html())

Previous: Node's question about the request header

Next: Sliding CAPTCHA of python selenium simulation crawler

Regular matching intercept replacement problem
Raw data: n2412 n : n2 ... : ...

Javascript javascript-regular regular-expression vue.js

Mar.10,2021
Regular how to remove the left and right spaces of specified characters in a string
for example: aa A1:B2 v2VR b3 want to get: aa A1:B2 v2VR b3 ...

Regular-expression javascript javascript-regular

Mar.20,2021
How do I get the value of arguments in the repalce callback function?
javascript：repalce (regEx,Fn) how to get the value of arguments in the callback function Fn () sources of topics and their own ideas an example in the extension of regular expression in Chapter 5 of Ruan Yifeng s introduction to ES6, runtime erro...

Javascript javascript-regular

Apr.07,2021
Pay to help write a js rule
means that users can post links and pictures, but cannot send html and css styles! the current way of writing is: var result=str.replace( (< ?)([a-z]+)( s[ w W]*?)?(>) ig,function(s0,s1,s2,s3,s4) { if (! ^(img|a)$ .test(s2)) return &q...

Regular-expression javascript javascript-regular

Apr.07,2021
Js regular validation of js expressions and value?
var key = ? (key) var str1 = `{{${key} ? ${key}: nihao }}` var str2 = `{{ ${key} && nihao }}` var str3 = `{{ nihao || ${key} }}` reg.test(str1) && reg.test(str2) && reg.test(str3) === true reg =? ...

Regular-expression javascript javascript-regular

Jun.07,2021
How to write regular expressions?
problem description validate the entered data. You can only enter data between 0 and 1. 0 cannot be entered, 1 can be entered, and there are only 2 decimal places. How to write a regular expression with only 2 decimal places? 0.0 and 0.00 also fail v...

Javascript javascript-regular iview vue.js

Dec.28,2021
Please tell me how js finds strings contained in certain characters through regularization.
for example, there is a paragraph of markdown . -sharp-sharp mysql >mysql MySQL Command Line Client mysql; ; ![image](http: localhost:3000 images markdown image-1551081068552-11.png) [http: localhost:8081 markdown 3](http: localhost:8081 mar...

Regular-expression javascript javascript-regular

Jul.14,2022

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b317e4-34165.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b317e4-34165.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?