前六个手机号码不应该相同[关闭]

Question

I need to find if the mobile number contain the first 6 digit same or not.

the last five numbers could be the same.

But i need to check if only the first 6 number are same

say for example if have a mobile number, 8999999589 then there should not be any consecutive 6 number at any point.

Answer 1

Dumb and fast way, use regexes :

const falseNumber = '66666655555';
const trueNumber = '12345655555';

const isFalse = function (num) {
  const regex = new RegExp('^(' + new Array(10)
    .fill(0)
    .map((v, i) => new Array(6).join(i))
    .join('|') + ')');
  return !regex.exec(num);
}

console.log(falseNumber + ' is ' + isFalse(falseNumber));
console.log(trueNumber + ' is ' + isFalse(trueNumber));

You can even shorten it : if you can replace the six same first numbers, then it's false.

const falseNumber = '66666655555';
const trueNumber = '12345655555';

function isFalse(num) {
  return num.replace(/^(\d)\1{5}/, '').length !== num.length;
}

console.log(falseNumber + ' is ' + isFalse(falseNumber));
console.log(trueNumber + ' is ' + isFalse(trueNumber));

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