javascript - 有没有办法在javascript中将子数组和子子数组合并为一个？

Question

let arr = [A, B, C, [D, E, F, [G, H, I]]];
我尝试了很多数组方法，但最终没有得到预期的结果。
我需要这样的输出
let arr = [A, B, C, D, E, F, G, H, I];

Answer 1

你可以这样做，

const arrays = ["A", "B", "C", ["D", "E", "F", ["G","H", "I"]]];
const merge3 = arrays.flat(2); //The depth level specifying how deep a nested array structure should be flattened. Defaults to 1.
console.log(merge3);