push()无法在reduce()中按预期方式工作 [英] push() won't work as expected in reduce()

问题描述

为什么 a.push(b)在我的 Array.reduce()中不起作用?a = a.push(b)，其中 b 是一个字符串，将 a 转换为整数.

Why doesn't a.push(b) work in my Array.reduce()? a=a.push(b) where b is a string, turns a to an integer.?!

 getHighestValuesInFrequency: function(frequency) {
 //Input:var frequency = {mats: 1,john: 3,johan: 2,jacob: 3};
 //Output should become ['John','jacob']

var objKeys = Object.keys(frequency);
var highestVal = objKeys.reduce((a,b)=>
            {highestVal = (frequency[b] > a)? frequency[b] : a;
             return highestVal;},0);

var winner = objKeys.reduce((a,b)=>
      { a = (frequency[b] === highestVal)? a.push(b) : a;
        return a},[]);

return winner;  
 }                                  

推荐答案

由于 push()返回数组的新长度，因此您正在将长度分配给 a .代替条件运算符，请使用 if 语句.

Since push() returns the new length of the array, you're assigning the length to a. Instead of a conditional operator, use an if statement.

var winner = objKeys.reduce((a, b) => {
    if (frequency[b] === highestVal) {
        a.push(b);
    }
    return a;
}, []);

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