25 JS regular expressions commonly used in front-end form validation

1. Mobile phone number verification

const phoneReg = /^[1][3,4,5,6,7,8,9][0-9]{9}$/

const phoneStr1 = '18886233487'
console.log(phoneReg.test(phoneStr1)) // true

const phoneStr2 = '17283017203897'
console.log(phoneReg.test(phoneStr2)) // false

2. ID card verification

const sfzReg = /^[1-9]\d{5}(18|19|([23]\d))\d{2}((0[1-9])|(10|11|12))(([0-2][1-9])|10|20|30|31)\d{3}[0-9Xx]$/

const sfzStr1 = '415106199801012130'
console.log(sfzReg.test(sfzStr1)) // true

const sfzStr2 = '718381298381212183'
console.log(sfzReg.test(sfzStr2)) // false

3. Mailbox verification

const emailReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/

const emailStrWY = '[e-mail]' // 163邮箱
const emailStrQQ = '[e-mail]' // qq邮箱
console.log(emailReg.test(emailStrWY)) // true
console.log(emailReg.test(emailStrQQ)) // true

const noEmail = '72873213.com'
console.log(emailReg.test(noEmail)) // false

4. URL verification

const urlReg = /^((https?|ftp|file):\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/

const urlStr1 = 'https://haha.sunshine.com/xxx/xxx'
console.log(urlReg.test(urlStr1)) // true

const urlStr2 = 'sss://haha.sunshine.com/xxx/xxx'
console.log(urlReg.test(urlStr2)) // false

5. IPv4 verification

const ipv4Reg = /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/

const ipv4Str1 = '122.12.56.65'
console.log(ipv4Reg.test(ipv4Str1)) // true

const ipv4Str2 = '122.12.56.655'
console.log(ipv4Reg.test(ipv4Str2)) // false

6, hexadecimal color check

const color16Reg = /^#?([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$/

const color16Str1 = '#fff'
console.log(color16Reg.test(color16Str1)) // true

const color16Str2 = '#1234567'
console.log(color16Reg.test(color16Str2)) // false

7. Date YYYY-MM-DD

const dateReg = /^\d{4}(\-)\d{1,2}\1\d{1,2}$/

const dateStr1 = '2021-10-10'
console.log(dateReg.test(dateStr1)) // true

const dateStr2 = '2021-01-01 1'
console.log(dateReg.test(dateStr2)) // false

8. Date YYYY-MM-DD hh:mm:ss

const dateReg = /^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2}) (\d{1,2}):(\d{1,2}):(\d{1,2})$/

const dateStr1 = '2021-10-10 16:16:16'
console.log(dateReg.test(dateStr1)) // true

const dateStr2 = '2021-10-10 16:'
console.log(dateReg.test(dateStr2)) // false

9. Integer checksum

const intReg = /^[-+]?\d*$/

const intNum1 = 12345
console.log(intReg.test(intNum1)) // true

const intNum2 = 12345.1
console.log(intReg.test(intNum2)) // false

10. Decimal checksum

const floatReg = /^[-\+]?\d+(\.\d+)?$/

const floatNum = 1234.5
console.log(floatReg.test(floatNum)) // true

11. Keep n decimal places

function checkFloat(n) {
  return new RegExp(`^([1-9]+[\d]*(.[0-9]{1,${n}})?)$`)
}
// 保留2位小数
const floatReg = checkFloat(2)

const floatNum1 = 1234.5
console.log(floatReg.test(floatNum1)) // true

const floatNum2 = 1234.55
console.log(floatReg.test(floatNum2)) // true

const floatNum3 = 1234.555
console.log(floatReg.test(floatNum3)) // false

12. Check the postal code

const postalNoReg = /^\d{6}$/

const postalNoStr1 = '522000'
console.log(postalNoReg.test(postalNoStr1)) // true

const postalNoStr2 = '5220000'
console.log(postalNoReg.test(postalNoStr2)) // false

13. Check of QQ number (5-11 digits)

const qqReg = /^[1-9][0-9]{4,10}$/

const qqStr1 = '1915801633'
console.log(qqReg.test(qqStr1)) // true

const qqStr2 = '191580163333'
console.log(qqReg.test(qqStr2)) // false

14. Wechat verification (6 to 20 digits, starting with letters, letters, numbers, minus signs, underscores)

const wxReg = /^[a-zA-Z]([-_a-zA-Z0-9]{5,19})+$/

const wxStr1 = 'linsanxin885577'
console.log(wxReg.test(wxStr1)) // true

const wxStr2 = '厉害了我的vx'
console.log(wxReg.test(wxStr2)) // false

15. Verification of license plate number

const carNoReg = /^[京津沪渝冀豫云辽黑湘皖鲁新苏浙赣鄂桂甘晋蒙陕吉闽贵粤青藏川宁琼使领A-Z]{1}[A-Z]{1}[A-Z0-9]{4}[A-Z0-9挂学警港澳]{1}$/

const carNoStr1 = '粤A12345'
console.log(carNoReg.test(carNoStr1)) // true

const carNoStr2 = '广东A12345'
console.log(carNoReg.test(carNoStr2)) // false

16, a character string containing only letters

const letterReg = /^[a-zA-Z]+$/

const letterStr1 = 'sunshineLin'
console.log(letterReg.test(letterStr1)) // true

const letterStr2 = 'sunshine_Lin'
console.log(letterReg.test(letterStr2)) // false

17, a character string containing Chinese

const cnReg = /[\u4E00-\u9FA5]/

const cnStr1 = '我是sunshine_Lin，林三心'
console.log(cnReg.test(cnStr1)) // true

const cnStr2 = 'sunshine_Lin'
console.log(cnReg.test(cnStr2)) // false

18. Password strength verification (the password must contain letters, numbers, special characters, at least 8 characters, and a maximum of 30 characters)

const passwordReg = /(?=.*[0-9])(?=.*[a-zA-Z])(?=.*[^a-zA-Z0-9]).{8,30}/

const password1 = 'sunshine_Lin12345..'
console.log(passwordReg.test(password1)) // true

const password2 = 'sunshineLin12345'
console.log(passwordReg.test(password2)) // false

19. Check the string length n

function checkStrLength(n) {
  return new RegExp(`^.{${n}}$`)
}

// 校验长度为3的字符串
const lengthReg = checkStrLength(3)

const str1 = 'hhh'
console.log(lengthReg.test(str1)) // true

const str2 = 'hhhhh'
console.log(lengthReg.test(str2)) // false

20. Check the file extension

function checkFileName (arr) {
  arr = arr.map(name => `.${name}`).join('|')
  return new RegExp(`(${arr})$`)
}

const filenameReg = checkFileName(['jpg', 'png', 'txt'])

const filename1 = 'sunshine.jpg'
console.log(filenameReg.test(filename1)) // true
const filename2 = 'sunshine.png'
console.log(filenameReg.test(filename2)) // true
const filename3 = 'sunshine.txt'
console.log(filenameReg.test(filename3)) // true
const filename4 = 'sunshine.md'
console.log(filenameReg.test(filename4)) // false

21. Match img and src

const imgReg = /<img.*?src=[\"|\']?(.*?)[\"|\']?\s.*?>/ig

const htmlStr = '<div></div><img src="sunshine.png" /><img src="sunshine111.png" />'

console.log(imgReg.exec(htmlStr))
// [
//   '<img src="sunshine.png" />',
//   'sunshine.png',
//   index: 11,
//   input: '<div></div><img src="sunshine.png" /><img src="sunshine111.png" />',
//   groups: undefined
// ]
console.log(imgReg.exec(htmlStr))
// [
//   '<img src="sunshine111.png" />',
//   'sunshine111.png',
//   index: 37,
//   input: '<div></div><img src="sunshine.png" /><img src="sunshine111.png" />',
//   groups: undefined
// ]

22, match the comment in html

const noteReg = /<!--(.*?)-->/g

const htmlStr = '<!--一个div标签--> <div></div> <!--一个div标签--> <div></div>'

console.log(noteReg.exec(htmlStr))
// [
//   '<!--一个div标签-->',
//   '一个div标签',
//   index: 0,
//   input: '<!--一个div标签--> <div></div> <!--一个div标签--> <div></div>',
//   groups: undefined
// ]
console.log(noteReg.exec(htmlStr))
// [
//   '<!--一个div标签-->',
//   '一个div标签',
//   index: 27,
//   input: '<!--一个div标签--> <div></div> <!--一个div标签--> <div></div>',
//   groups: undefined
// ]

23. Match the style in html

const styleReg = /([(\s+\w+=)|>])/g

const htmlStr = '<div><span></span></div>'

console.log(styleReg.exec(htmlStr))
// [
//   '>',
//   '>',
//   index: 5,
//   input: '<div><span></span></div>',
//   groups: undefined
// ]
console.log(styleReg.exec(htmlStr))
// [
//   '>',
//   '>',
//   index: 36,
//   input: '<div><span></span></div>',
//   groups: undefined
// ]

24, match the color in html

const colorReg = /#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/g

const htmlStr = '<div><span></span></div>'

console.log(colorReg.exec(htmlStr))
// [
//   '#000',
//   '000',
//   index: 23,
//   input: '<div><span></span></div>',
//   groups: undefined
// ]
console.log(colorReg.exec(htmlStr))
// [
//   '#fff',
//   'fff',
//   index: 49,
//   input: '<div><span></span></div>',
//   groups: undefined
// ]

25, match htmlTag (html tag)

const endReg = /<("[^"]*"|'[^']*'|[^'">])*>/g

const htmlStr = '<div><span></span></div><h1></h1>'

console.log(endReg.exec(htmlStr))