问题
我有一个像这样的数组:
let oddsArray = [undefined, undefined, 5, 5]
和一个还原功能:
const reducer = (accumulator, currentValue) => accumulator + currentValue
当我调用console.log时,我得到了:
console.log(oddsArray.reduce(reducer, 1), 'oddsArray') /// NAN
直到数组不再包含未定义:
[5, 5, 5, 5] /// 20
我想发生的事情
即使该数组中包含不确定的值,我也希望能够添加数组中的所有数字。因此,初始数组应该等于:
let oddsArray = [undefined, undefined, 5, 5] // 10
我该如何实现?
谢谢!
您可以检查undefined
值,如下:currentValue || 0
let oddsArray = [undefined, undefined, 5, 5]
const reducer = oddsArray.reduce((accumulator, currentValue) =>
accumulator + (currentValue || 0), 0);
console.log(reducer);
如果您需要一种更通用的方法,即仅总结具有多种类型元素的数组上的数字,则可以使用number.isnan()检查当前的数字。reducer
的值是否为数字:
let oddsArray = [undefined, undefined, 5, 5, null, "hola", {"foo":"bar"}];
const reducer = (acc, currVal) => acc + (isNaN(currVal) ? 0 : currVal);
let res = oddsArray.reduce(reducer, 0);
console.log(res);
.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}