javascript - 如何将数组从 ["1","2","3","4"] 转换为 [1,2,3,4]？

Question

这个问题已经有答案了:

How to force JS to do math instead of putting two strings together [duplicate] (11 个回答)

已关闭 4 年前。

我正在尝试使用以下代码行 block

var myarray = [1,2,3,4];
var new_array = [];
myarray.reduce(function(a,b,i) { return new_array[i] = a+b; },0);
// Result = [1, 3, 6, 10]
console.log("original array");
console.log(new_array);

这个 block 工作得很好，但是当我替换我自己的数组时，结果完全错误

var ar1 = ["1","2","3","4"];
var ar2 = [];
ar1.reduce(function(a,b,i) { return ar2[i] = a+b; },0);
// result = ["01", "012", "0123", "01234"]
console.log("original array");
console.log(ar2);

我得到这个结果[“01”，“012”，“0123”，“01234”]

谁能帮忙，谢谢

Answer 1

在使用+运算符之前，尝试parseInt将Number转换为String。 String + String 是字符串连接，而 Number + Number 是代数加法

var ar1 = ["1","2","3","4"];
var ar2 = [];
ar1.reduce(function(a,b,i) { return ar2[i] = parseInt(a) + parseInt(b); },0);
// result = ["01", "012", "0123", "01234"]
console.log("original array");
console.log(ar2);