将整数拆分为 2 位数字并放入数组 Javascript

Question

（必须阅读以了解我需要什么） 我想创建一个程序，输入一个数字，例如：12345，然后将此数字拆分为 2 位数字并将其存储在一个数组中。数组必须如下所示： [0]=45 [1]=23 [2]=1 。这意味着数字的拆分必须从数字的最后一位而不是第一位开始。

这是我到现在为止的：

var splitCount = []; // This is the array in which we store our split numbers
//Getting api results via jQuery's GET request
$.get("https://www.googleapis.com/youtube/v3/channels?part=statistics&id=UCJwchuXd_UWNxW-Z1Cg-liw&key=AIzaSyDUzfsMaYjn7dnGXy9ZEtQB_CuHyii4poc", function(result) {
    //result is our api answer and contains the recieved data
    //now we put the subscriber count into another variable (count); this is just for clarity
    count = result.items[0].statistics.subscriberCount;
    //While the subscriber count still has characters
    while (count.length) {
        splitCount.push(count.substr(0, 2)); //Push first two characters into the splitCount array from line 1
        count = count.substr(2); //Remove first two characters from the count string
    }       
    console.log(splitCount) //Output our splitCount array
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

但问题在于，如果有 5 个数字，例如：12345，最后一个数字将单独存在于一个数组中，如下所示：[0]=12 [1]=34 [2]=5 但我需要最后一个数组有 2 个数字，第一个应该是一个数字，而不是像这样：[0]=1 [1]=23 [2]=45

Answer 1

对奇数和偶数字符串长度使用不同的正则表达式拆分字符串，Array#map 使用Number 和Array#reverse 数组：

function splitToNumbers(str) {
  return str.match(str.length  % 2 ? /^\d|\d{2}/g : /\d{2}/g).map(Number).reverse()
}
    
console.log(splitToNumbers('1234567'));

console.log(splitToNumbers('123456'));

Answer 2

这是一个完成任务的sn-p。该函数将值存储在数组myArray 中，然后将数组输出到<p> 元素。在输入框中输入数字。以后可以随意更改。

function myFunction() {
  // Input field
  var input = document.getElementById('num');1
  // Length of the array storing the numbers
  var myArraySize = Math.floor(input.value.length / 2) + (input.value.length % 2);
  // The array storing the numbers
  var myArray = [];
  
  for (var i = 0; i < myArraySize; i++) {
    myArray[i] = input.value.slice(2*i,2*i+2);
  }
  // Output the array
  document.getElementById('demo').innerHTML = myArray;
}

<input id="num" type="text" onkeyup="myFunction()" />
<p id="demo">Result</p>

Answer 3

您可以使用正则表达式拆分字符串并反转数组。

这个答案深受answer 的启发。

var regex = /(?=(?:..)*$)/;

console.log('12345'.split(regex).reverse());
console.log('012345'.split(regex).reverse());

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 4

无需正则表达式或昂贵的计算。您可以简单地执行以下操作；

var n = 250847534,
steps = ~~Math.log10(n)/2,
  res = [];
for(var i = 0; i <= steps; i++) {
  res.push(Math.round(((n /= 100)%1)*100));
  n = Math.trunc(n);
}
console.log(res);

Answer 5

稍微修改你的代码

var splitCount = []; // This is the array in which we store our split numbers
//Getting api results via jQuery's GET request
$.get("https://www.googleapis.com/youtube/v3/channels?part=statistics&id=UCJwchuXd_UWNxW-Z1Cg-liw&key=AIzaSyDUzfsMaYjn7dnGXy9ZEtQB_CuHyii4poc", function(result) {
    //result is our api answer and contains the recieved data
    //now we put the subscriber count into another variable (count); this is just for clarity
    count = result.items[0].statistics.subscriberCount;
    //While the subscriber count still has characters
    while (count.length) {
        splitCount.push(count.substr(-2)); //Push last two characters into the splitCount array from line 1
        if(count.length > 1) {
           count =  count.substr(0, count.length - 2); //Remove first last two characters from the count string
        } else {
           break;
        }
    }       
    console.log(splitCount) //Output our splitCount array
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Answer 6

有几种方法可以解决您的问题，从使用正则表达式（如 Ori Dori 或 Nina Scholz）的漂亮单行代码到直接处理数字而不使用字符串的 Redu's answer。

按照您的代码示例和 cmets 的逻辑，这里有一个替代方法，它将数字转换为字符串，向后循环以一次提取两个数字，将它们转换回数字（使用一元加号运算符） ，并将此数字输出到结果数组：

function extract(num) {
  var s = '0' + num, //convert num to string
    res = [],
      i;
  for(i = s.length; i > 1; i -= 2) {
    //loop from back, extract 2 digits at a time, 
    //output as number,
    res.push(+s.slice(i - 2, i));
  }
  return res;
}

//check that 12345 outputs [45, 23, 1]
console.log(extract(12345));

//check that 123456 outputs [56, 34, 12]
console.log(extract(123456));