多维数组转化成一维数组

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

let str = JSON.stringify(arr);

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1.直接调用

arr_flat = arr.flat(Infinity);

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2.

arr = str.replace(/(\[\]))/g, '').split(',');

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3.

str = str.replace(/(\[\]))/g, '');

str = '[' + str + ']';

arr = JSON.parse(str);

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4.递归处理

let result = [];

let fn = function(arr) {

    for(let i = 0; i < arr.length; i++){

        let item = arr[i];

        if (Array.isArray(arr[i])){

            fn(item);

        } else {

            result.push(item);

        }

   }
  
}

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5.用 reduce 实现数组的 flat 方法

function flatten(ary) {

    return ary.reduce((pre, cur) => {

        return pre.concat(Array.isArray(cur) ? flatten(cur) : cur);

    })

}


let arr = [1, 2, [3, 4], [5, [6, 7]]];

console.log(arr.MyFlat(Infinity))

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6.扩展运算符

while (arr.some(Array.isArray)) {

    arr = [].concat(...ary);

}