Question

我想用另一个数组中的值修改以下forEach结果，但无法正常工作。

const BbDescriptionDictionary = ['AAA' , 'BBB', 'CCC',] 
const boardBasisOptionsModified = [];  

this.boardBasisOptions.forEach( (value) => {
    boardBasisOptionsModified.push({ 
        "key": value, "value": BbDescriptionDictionary[value] 
    });  
});

this.boardBasisOptions = boardBasisOptionsModified;

Answer 1

您可以为.forEach提供第二个参数，以指示boardBasisOptions的索引。像这样：

this.boardBasisOptions.forEach( (value, index) => {
    boardBasisOptionsModified.push({ 
        "key": value, "value": BbDescriptionDictionary[index] 
    });  
});

Answer 2

您可能想在index循环中添加forEach参数：
（我还用一些值初始化了boardBasisOptions）

请参见以下工作片段：

boardBasisOptions = ['key1', 'key2', 'key3'];
const BbDescriptionDictionary = ['AAA', 'BBB', 'CCC', ]
const boardBasisOptionsModified = [];

this.boardBasisOptions.forEach((value, index) => {
  boardBasisOptionsModified.push({
    "key": value,
    "value": BbDescriptionDictionary[index]
  });
});

this.boardBasisOptions = boardBasisOptionsModified;

console.log("boardBasisOptions:");
console.log(this.boardBasisOptions);

Answer 3

您试图使用值而不是索引访问BbDescriptionDictionay数组中的值。您必须使用索引来访问数组的值。

只需将index添加为forEach函数的第二个参数即可。

this.boardBasisOptions.forEach( (value, index) => {
   boardBasisOptionsModified.push({ 
      "key": value, "value": BbDescriptionDictionary[index] 
   });  
});

Answer 4

通过获取索引，您可以使用Array#map代替Array#push。

const BbDescriptionDictionary = ['AAA', 'BBB', 'CCC',] 

this.boardBasisOptions = this
    .boardBasisOptions
    .map((key, index) => ({ key, value: BbDescriptionDictionary[index] }));

Answer 5

您应该只使用from . import gender # pragma: no cover, NOQA: F401来创建一个新的变异数组，而不用担心创建临时数组，对其进行变异然后分配它们。

Array.prototype.map()

覆盖这样的属性被认为是不好的做法，因此我将原来的const BbDescriptionDictionary = ['AAA' , 'BBB', 'CCC',] // Map runs the function on each array item and returns a new array // with mutated the return value of that function // Note: ({ ... }) is a shorthand way of returning a value // (object in this case) without a function body {} this.boardBasisOptions = this.boardBasisOptions.map((key, index) => ({ // Shorthand way of assigning a variable to an object using the var // name as the key key, value: BbDescriptionDictionary[index] })返回到新属性，并在以后使用它：

boardBasisOptions

希望有帮助

使用来自另一个数组的值修改javascript forEach结果

5 个答案: