js作用域 concat

let newArray = array1.concat(array2, array3, ..., arrayX);

let array1 = [1, 2, 3];
let array2 = [4, 5, 6];

// 合并两个数组
let combinedArray = array1.concat(array2);
console.log(combinedArray); // 输出: [1, 2, 3, 4, 5, 6]

// 合并数组和值
let arrayWithValue = array1.concat(7, 8);
console.log(arrayWithValue); // 输出: [1, 2, 3, 7, 8]

// 复制数组
let copiedArray = array1.concat();
console.log(copiedArray); // 输出: [1, 2, 3]

function deepConcat(arrays) {
  return arrays.reduce((acc, curr) => {
    return acc.concat(Array.isArray(curr) ? deepConcat(curr) : curr);
  }, []);
}

let nestedArray1 = [1, [2, 3]];
let nestedArray2 = [[4], 5];

let deeplyCombinedArray = deepConcat([nestedArray1, nestedArray2]);
console.log(deeplyCombinedArray); // 输出: [1, 2, 3, 4, 5]