JS如何判断input中密码输入的数字是否为连续数字？

Question

6位支付密码设置，如何判断input中输入的数字是否为连续数字？如果是则提醒用户安全较低。例如：333333，这是6位的相同的123456或234567或987654，这种连续的使用JS的.test()来判断，正则应该怎么写？

Answer 1

没有想到正则的方法，自己写了一个函数：

检测序列是0123456789:

function isContinue(str) {

  let diff = +str[1] - +str[0]

  diff = diff < 0 ? diff + 10 : diff

  let former = +str[0]

  for (let i = 1; i < str.length; i++) {

    let cur0 = +str[i]

    let cur1 = former + diff

    cur1 = cur1 < 0 ? cur1 + 10 : cur1 % 10

    if (cur0 !== cur1) return false

    former = cur0

  }

  return true

}

console.log(isContinue('987654')) // true

console.log(isContinue('432109')) // true

console.log(isContinue('123456')) // true

console.log(isContinue('901234')) // true

console.log(isContinue('201235')) // false

检测的序列是123456789:

function isContinue(str) {

  let base = 9

  let strArray = []

  for (let i = 0, len = str.length; i < len; i++) {

    let j = +str[i] - 1

    strArray[i] = j < 0 ? j + base : j

  }

  str = strArray.join('')

  let diff = +str[1] - +str[0]

  diff = diff < 0 ? diff + base : diff

  let former = +str[0]

  for (let i = 1; i < str.length; i++) {

    let cur0 = +str[i]

    let cur1 = former + diff

    cur1 = cur1 < 0 ? cur1 + base : cur1 % base

    if (cur0 !== cur1) return false

    former = cur0

  }

  return true

}

console.log(isContinue('987654')) // true

console.log(isContinue('432198')) // true

console.log(isContinue('123456')) // true

console.log(isContinue('912345')) // true

console.log(isContinue('901234')) // false

Answer 2

function fun(str) {

    if (str.length < 2)

        return false;

    var t = str.charCodeAt(0) - str.charCodeAt(1);

    for (var i = 0,l=str.length; i < l - 1; i++)

        if ((str.charCodeAt(i) - str.charCodeAt(i + 1)) != t)

            return false;

    return true;

}

fun('123456')

正则的话太麻烦了