Weight for weight JavaScript趣题:减肥俱乐部

Description:

My friend John and I are members of the "Fat to Fit Club (FFC)". John is worried because each month a list with the weights of members is published and each month he is the last on the list which means he is the heaviest.

I am the one who establishes the list so I told him: "Don't worry any more, I will modify the order of the list". It was decided to attribute a "weight" to numbers. The weight of a number will be from now on the sum of its digits.

For example

99 will have "weight" 18, 100 will have "weight" 1 so in the list 100 will come before 99. Given a string with the weights of FFC members in normal order can you give this string ordered by "weights" of these numbers?
Example:

"56 65 74 100 99 68 86 180 90" ordered by numbers weights becomes: "100 180 90 56 65 74 68 86 99"

All numbers in the list are positive numbers and the list can be empty.

console.log(orderWeight("56 65 74 100 99 68 86 180 90"));//100 180 90 56 65 74 68 86 99

方法一

function orderWeight(strng) {
    var arr=strng.split(' ');
    arr.sort(function(a,b){
      var num1=0;
      var num2=0;
      for(var i=0;i<a.length;i++){
        num1+=a[i]*1;  //把字符串转换成数字类型
      }
      for(var i=0;i<b.length;i++){
        num2+=b[i]*1;
      }
      return num1-num2||a.localeCompare(b);
    })
    return arr.join(' ')
}

方法二：使用 < key,value >键值对

function orderWeight(strng) {
  return strng
    .split(" ")
    .map(function(v) {  
      return {
        val: v,
        key: v.split("").reduce(function(prev, curr) {
          return parseInt(prev) + parseInt(curr);
        }, 0)
      };
    })
    .sort(function(a, b) {
      return a.key == b.key 
        ? a.val.localeCompare(b.val)
        : (a.key - b.key);
    })
    .map(function(v) {
      return v.val;
    })
    .join(" ");
}