方案 1：设置条件（flag）
const arr = [0, 1, 2, 3, 4]
const sum = arr.reduce((prev, curr, index, currArr) => {
if (index >= 4) {
return prev
} else {
prev += curr
return prev
}
}, 0)
console.log(sum) // 6
方案 2：循环过程中修改原始数组
const arr = [0, 1, 2, 3, 4]
const sum = arr.reduce((prev, curr, index, currArr) => {
prev += curr
if (curr === 3) currArr.length = 0
return prev
}, 0)
console.log(sum) // 6
"如何跳出 reduce 循环"继续阅读