将 json 从 string 操作为 int 并对其进行计算

Question

enter image description here我有一个这样的数字列表：

"2552086989552589"
"6724843711060148"
"9758289300869651"
"5048166833276726"
"2864448008247645"
"6803999652011971"
"9758289300869650"
"9083938527182086"
"4563447869509114"
"2552086989552588"
"6724843711060149"
"6803999652011970"
"4563447869509115"
"3227366834142384"
"3227366834142385"
"5048166833276727"
"5153186889177226"
"2864448008247644"
"9083938527182087"

它们是这个函数的输出

function validate (ban,cards){
return cards;
}

我怎样才能得到卡片的输出并进行计算，例如“123123123”中数字的两倍之和，这些也是当前的字符串，所以需要先转换为int！

目标是

    {"card":"2552086989552589","isValid":false,"isAllowed":true}
{"card":"6724843711060148","isValid":true,"isAllowed":true}
{"card":"9758289300869651","isValid":false,"isAllowed":false}
{"card":"5048166833276726","isValid":true,"isAllowed":false}
{"card":"2864448008247645","isValid":false,"isAllowed":true}
{"card":"6803999652011971","isValid":false,"isAllowed":true}
{"card":"9758289300869650","isValid":true,"isAllowed":false}
{"card":"9083938527182086","isValid":true,"isAllowed":false}
{"card":"4563447869509114","isValid":true,"isAllowed":true}
{"card":"2552086989552588","isValid":true,"isAllowed":true}
{"card":"6724843711060149","isValid":false,"isAllowed":true}
{"card":"6803999652011970","isValid":true,"isAllowed":true}
{"card":"4563447869509115","isValid":false,"isAllowed":true}
{"card":"3227366834142384","isValid":true,"isAllowed":true}
{"card":"3227366834142385","isValid":false,"isAllowed":true}
{"card":"5048166833276727","isValid":false,"isAllowed":false}

有效是取前 15 个数字，将它们加倍，求和，然后除以 10。如果余数是最后一个数字，则 isvalid 为真，isallowed 为真。

更新

这非常接近工作：

 function validateCards(bannedPrefixes, cardsToValidate) {
return cardsToValidate.map(function(card) {
    const digits = card.split ('').map(Number);
    const valid = digits.reduce ((acc,d)=>acc+d*2, 0)%10== digits[digits.length-1]
    return {
        card: card,
        isValid: valid,
        isAllowed: valid,
    }
})
}

我只需要看看cardstovalidate是否包含禁止前缀，是否需要返回false

Answer 1

您需要拆分数字，然后转换数字，将它们乘以 2，然后将它们相加并检查模数是否等于最后一个数字。所以做这样的事情：

function validate (ban,cards) {
  return cards.map(
    function(card) {
        const digits = card.split('').map(Number);
        const isValid = digits.slice(0,15).reduce((acc,d) => (acc+d*2), 0)%10 == digits[digits.length-1];
        const isAllowed = isValid && ban.reduce((acc,f) => (card.match(`^${f}`) == null && acc),true)
        return {
            card: card,
            isValid: isValid,
            isAllowed: isAllowed,
        }
    });
}

Answer 2

function toDigits(str) { return str.split('').map(Number); }

function sum(accumulator, value) { return accumulator + value; }

function isCardValid(str) {
  var digits = toDigits(str);
  var sumOfFirst15 = digits.slice(0,15).reduce(sum, 0);
  var remainder = (2 * sumOfFirst15) % 10;
  return remainder === digits[digits.length - 1];
}

function isCardAllowed(ban, card) {
  for (var i = 0; i < ban.length; i += 1) {
    if (card.indexOf(ban[i]) !== -1) {
      return false;
    }
  }
  return true;
}

function toCardWithValidation(card) {
  var isValid = isCardValid(card);
  return {
    card: card,
    isValid: isValid,
    isAllowed: isCardAllowed(ban, card),
  };
}

cards.map(toCardWithValidation);