Question

我有多个带有动态名称（编号）的数组，我需要从每个数组中获取第一个值。

代码看起来像这样

    var array1 = ["1","2","3"];
    var array2 = ["1","2","3"];
    var array3 = ["1","2","3"];

    for (var cols=1; cols <=5; cols++) {
        var imgs = array.cols[0];
    }

我在控制台中收到“（（索引）：131 Uncaught ReferenceError：未定义数组）”

Answer 1

我了解到您想获得每个数组的"1","1","1"首个值。

您可以创建一个数组来存储所有3个数组
在错误阵列上使用map()
在map()内部，返回数组的第一个元素。

var array1 = ["1","2","3"];
var array2 = ["1","2","3"];
var array3 = ["1","2","3"];

let arrays = [array1,array2,array3];

let res = arrays.map(([a]) => a);

console.log(res);

Answer 2

如果您的数组在全局范围内，也许您可以使用window对象访问它们：

var array1 = ["1","2","3"];
var array2 = ["1","2","3"];
var array3 = ["1","2","3"];

for (let i = 1; i <= 3; i++)
{
    console.log(window["array" + i][0]);
}

另一个更通用的替代方法是将数组保存在另一个结构中，例如Map或Array。我将展示如何使用Map做到这一点：

let array1 = ["1","2","3"];
let array2 = ["1","2","3"];
let array3 = ["1","2","3"];
let myMap = new Map([["1", array1], ["2", array2], ["3", array3]]);

myMap.forEach(([first, ...rest]) => console.log(first));

遍历动态命名的数组

2 个答案: