javascript 有没有一种简单的方法可以使嵌套数组变平？
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Is there an easy way to make nested array flat?
提问by rsk82
That is to make this:
那就是要做到这一点：
[ ['dog','cat', ['chicken', 'bear'] ],['mouse','horse'] ]
[ ['dog','cat', ['chicken', 'bear'] ],['mouse','horse'] ]
into:
进入：
['dog','cat','chicken','bear','mouse','horse']
['dog','cat','chicken','bear','mouse','horse']
回答by ChewOnThis_Trident
var flattened = [[0, 1], [2, 3], [4, 5]].reduce(function(a, b) {
return a.concat(b);
});
// flattened is [0, 1, 2, 3, 4, 5]
It's note worthy that reduce isn't supported in IE 8 and lower.
值得注意的是，IE 8 及更低版本不支持 reduce。
回答by elclanrs
In modern browsers you can do this without any external libraries in a few lines:
在现代浏览器中，你可以在没有任何外部库的情况下通过几行来做到这一点：
Array.prototype.flatten = function() {
return this.reduce(function(prev, cur) {
var more = [].concat(cur).some(Array.isArray);
return prev.concat(more ? cur.flatten() : cur);
},[]);
};
console.log([['dog','cat',['chicken', 'bear']],['mouse','horse']].flatten());
//^ ["dog", "cat", "chicken", "bear", "mouse", "horse"]
回答by Craig M
Grab underscore.jsand use the flattenfunction.
获取underscore.js并使用flatten函数。
_.flatten([ ['dog','cat', ['chicken', 'bear'] ],['mouse','horse'] ]);
回答by vipin goyal
What about this one liner code ?
这一个班轮代码怎么样？
console.log([['dog', 'cat', ['chicken', 'bear']], [['mouse', 'horse'], 'lion']].join().split(','));basically join will make comma separated string from nested array and using split you can get 1d array, nice ? bonusit'll work on all major browsers as well :)
基本上 join 会从嵌套数组中生成逗号分隔的字符串，使用 split 你可以获得一维数组，好吗？奖金它也适用于所有主要浏览器:)
回答by Andrzej Sawoniewicz
Small fix for ChewOnThis_Trident solution and it works perfect:
ChewOnThis_Trident 解决方案的小修复，它完美运行：
Array.prototype.flatten = function() {
return this.reduce(function(a, b) {
return a.concat(b);
}, []);
};
回答by Alnitak
Assuming an array that's already unpacked from JSON, try this:
假设一个已经从 JSON 解包的数组，试试这个：
Array.prototype.flatten = function() {
var r = [];
for (var i = 0; i < this.length; ++i) {
var v = this[i];
if (v instanceof Array) {
Array.prototype.push.apply(this, v.flatten());
} else {
r.push(v);
}
}
return r;
};
It appears to work correctly on your input - see http://jsfiddle.net/alnitak/Ws7L5/
它似乎在您的输入上正常工作 - 请参阅http://jsfiddle.net/alnitak/Ws7L5/
回答by Code Maniac
Now in 2019you can easily use Array.flatwith whatever depth you want.
现在在 2019 年，您可以轻松地使用Array.flat任何您想要的深度。
let arr = [ ['dog','cat', ['chicken', 'bear'] ],['mouse','horse'] ]
let op = arr.flat(Infinity)
console.log(op)Now if you want to get unique values you can combine both Set and flat
现在如果你想获得唯一的值，你可以结合 Set 和 flat
let arr = [ ['dog','cat', ['chicken', 'bear', 'cat'] ],['mouse','horse', 'dog'], [[[['deeper','chicken']]]] ]
let unique = [...new Set(arr.flat(Infinity))]
console.log(unique)回答by maheshmnj
The easiest way of flattening the Objects of any depth would be using the flat method
展平任何深度的对象的最简单方法是使用 flat 方法
var arr = [['dog','cat', ['chicken', 'bear']],[['mouse','horse'],'lion'] ];
var flattened = arr.flat(Infinity);
//output--> ["dog", "cat", "chicken", "bear", "mouse", "horse", "lion"]
回答by TrojanMorse
I know this is late but I also ran into a situation where I needed to make a multidimensional array into 1 array and I made a function as follows.
我知道这已经晚了，但我也遇到了一种情况，我需要将一个多维数组变成 1 个数组，然后我创建了一个函数，如下所示。
function nested(arr) {
var noNest = arr.toString().split(',').filter(Boolean),
i = 0;
for(i;i<noNest.length; i++){
if(isNaN(noNest[i])){
return console.log(noNest);
} else {
noNest[i] = parseInt(noNest[i]);
}
}
return console.log(noNest);
}
nested([[['a']], [['b']]]);
This also take the nested arrays inside the tested array and makes sure its one array as the final out put
这也采用测试数组中的嵌套数组，并确保其一个数组作为最终输出
回答by Yup.
This solution has been working great for me, and i find it particularly easy to follow:
这个解决方案对我很有用，我发现它特别容易遵循：
function flattenArray(arr) {
// the new flattened array
var newArr = [];
// recursive function
function flatten(arr, newArr) {
// go through array
for (var i = 0; i < arr.length; i++) {
// if element i of the current array is a non-array value push it
if (Array.isArray(arr[i]) === false) {
newArr.push(arr[i]);
}
// else the element is an array, so unwrap it
else {
flatten(arr[i], newArr);
}
}
}
flatten(arr, newArr);
return newArr;
}
