在不使用嵌套 for 循环的情况下迭代 JavaScript 数组
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Iterate over a JavaScript array without using nested for-loops
提问by Anderson Green
I've been trying to iterate over a multidimensional array in JavaScript, and print each element in the array. Is there any way to print each element in a multidimensional array without using nested for-loops?
我一直在尝试在 JavaScript 中迭代一个多维数组，并打印数组中的每个元素。有没有办法在不使用嵌套 for 循环的情况下打印多维数组中的每个元素？
var arr = [[1, 5],[7, 4]];
for(var i in arr){
alert(i); //this displays "0", then displays "1",
//instead of printing each element in the array
//how can I make it print each element in each 2D array instead,
//without using nested for-loops for each dimension of the array?
}
回答by
Sounds like the issue is that you may have a nesting of arbitrary depth. In that case, use a recursive function.
听起来问题在于您可能有任意深度的嵌套。在这种情况下，请使用递归函数。
function printArray(arr) {
for (var i = 0; i < arr.length; i++)
if (Array.isArray(arr[i]))
printArray(arr[i])
else
console.log(arr[i])
}
The Array.isArraywill need a shim for older browsers.
在Array.isArray需要对旧版浏览器垫片。
if (!Array.isArray)
Array.isArray = function(o) {
return !!o && Object.prototype.toString.call(o) === "[object Array]"
}
回答by ZER0
If you don't want to use nested loops, you can either flat the array or use a recursive function. Something like:
如果您不想使用嵌套循环，您可以将数组平展或使用递归函数。就像是：
arr.forEach(function each(item) {
if (Array.isArray(item))
item.forEach(each);
else
console.log(item)
});
