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preface

Based on learning

Start with a small chestnut:

let req = '/at/gi'; // Matches all ats in the string case insensitive
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That’s what emmmm notes say, but what are we to make of it?

let req = '/pattern/flags'
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Pattern can be any simple or complex regular expression, including character classes, qualifiers, grouping, look-forward, and backreferencing

Flags, which control the behavior of the re, are covered directly

  • G: Global mode, which looks for the entire content of the string instead of finding the first match
  • I: Case insensitive, indicating that the case of pattern and string are ignored when searching for a match
  • M: Multi-line mode: the search continues after the end of a line of text
  • Y: in adhesive mode, the search continues after only the end of a line of text
  • U: Unicode mode, enabling Unicode matching
  • S: dotAll pattern, representing metacharacters, matching any character (including \n or \r)

Rich text intercepts internal content

var a = document.createElement("div") // Create a container to store rich text content
a.innerHTML = '<div>111<span>22222</span></div>'  // Add elements to the container
a.innerText / / "11122222"
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With or without decimals

function isDecimal(strValue)  {  
   var  objRegExp= /^\d+\.\d+$/;
   return  objRegExp.test(strValue);  
}  

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Verify whether the check is composed of Chinese names

function ischina(str) {
    var reg=/ ^ [\ u4E00 - \ u9FA5] {2, 4} $/;   /* Define the validation expression */
    return reg.test(str);     /* Verify */
}
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Check whether the check is made up of 8 digits

function isStudentNo(str) {
    var reg=/ ^ [0-9] {8} $/;   /* Define the validation expression */
    return reg.test(str);     /* Verify */
}
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Verify the phone code format

function isTelCode(str) {
    var reg= / ^ ((0 \ d {2, 3} - \ d {7, 8}) | (1 [3584] \ d {9})) $/;
    return reg.test(str);
}
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Verify that the email address is valid

function IsEmail(str) {
    var reg=/ ^ + @ \ w/a - zA - Z0-9] {2, 10} (? : \ [a-z] {2, 4}) $/ {1, 3};
    return reg.test(str);
}
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Replace specific files to preserve variables in the middle

The current demand is

< P > Small scraper refers to the bucket volume in 3m³ The following LDS. < / p > requirements:

  • Replace & sup3; < sup > 3 < / sup >

  • Keep & sup3; Constant in the middle

let str = '< P > Small scraper refers to the bucket volume of 3m³ The following LDS. 
'
str.replace(/&sup(.*?) ; /.'<sup>$1</sup>')
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Id number part shows hidden

IDcardNo() {
  const card = '123845785238542307'
  if (this.showIdCardNo) {
    console.log(1111)
    return card
  }
  // Intercepts the string from the third to last digits of the id number
  const reg = card.slice(3, -3)
  // Add * according to the truncated length
  const pad = The '*'.padStart(reg.length, The '*')
  return card.replace(reg, pad)
}
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String interception

analysisUrl(url: string): any {
  if (url) {
   // String interception
    url = url.substr(url.indexOf('? ') + 1)}// Create an object for name and value
  const result = {},
    queryString = url || location.search.substring(1), //location.search sets or returns from question mark (?) The starting URL (query section).
    re = /([^&=]+)=([^&]*)/g 
  let m: any = ' '
  while ((m = re.exec(queryString))) {
    //exec() matches regular expressions
    // Use decodeURIComponent() to decode the encoded URI
    result[decodeURIComponent(m[1=]]decodeURIComponent(m[2])}return result
}
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conclusion

Here are some tips for you! If you like it, please collect it. If you don’t like it, please make fun!