我有一个JavaScript数组,如:
[["$6"], ["$12"], ["$25"], ["$25"], ["$18"], ["$22"], ["$10"]]
如何将单独的内部数组合并为一个,例如:
["$6", "$12", "$25", ...]
我有一个JavaScript数组,如:
[["$6"], ["$12"], ["$25"], ["$25"], ["$18"], ["$22"], ["$10"]]
如何将单独的内部数组合并为一个,例如:
["$6", "$12", "$25", ...]
当前回答
您可以使用“join()”和“split()”:
设arrs=[["$6"],["$12"],["$25"],["$25"],["$18"],["$22"],["$10"]];让newArr=arrs.join(“,”).split(“,“);console.log(newArr);//["$6", "$12", "$25", "$25", "$18", "$22", "$10"]
此外,还可以使用“toString()”和“split()”:
设arrs=[["$6"],["$12"],["$25"],["$25"],["$18"],["$22"],["$10"]];让newArr=arrs.toString().split(“,”);console.log(newArr);//["$6", "$12", "$25", "$25", "$18", "$22", "$10"]
然而,如果字符串包含逗号,上述两种方式都不能正常工作:
“join()”和“split()”:
设arrs=[["$,6"],["$,12"],["$2,5"],["$2,5"],[",$18"],["$22,"],["$,1,0"]];让newArr=arrs.join(“,”).split(“,“);console.log(newArr);// ["$", "6", "$", "12", "$2", "5", "$2", "5", "", "$18", "$22", "", "$", "1", "0"]
“toString()”和“split()”:
设arrs=[["$,6"],["$,12"],["$2,5"],["$2,5"],[",$18"],["$22,"],["$,1,0"]];让newArr=arrs.toString().split(“,”);console.log(newArr);// ["$", "6", "$", "12", "$2", "5", "$2", "5", "", "$18", "$22", "", "$", "1", "0"]
其他回答
如何使用JavaScript 1.8的reduce(callback[,initialValue])方法
list.reduce((p,n) => p.concat(n),[]);
能胜任这项工作。
我写的简单的flatten util
const flatten = (arr, result = []) => {
if (!Array.isArray(arr)){
return [...result, arr];
}
arr.forEach((a) => {
result = flatten(a, result)
})
return result
}
console.log(flatten([1,[2,3], [4,[5,6,[7,8]]]])) // [ 1, 2, 3, 4, 5, 6, 7, 8 ]
简单并处理多个嵌套级别:
// deeply nested array
const myArray = [1, 2, [3, 4, [5, 6, [[[7,8, [[[[[9, 10]]]]]]]]]]] ;
const flatten = (arr) => {
for (let index = 0; index < arr.length; index++) {
const elem = arr[index];
if (Array.isArray(elem)) {
arr.splice(index, 1, ...elem);
index--;
}
}
};
flatten(myArray);
console.log(myArray); // [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
更简单和直接的方法;可选择深压平;
const flatReduce = (arr, deep) => {
return arr.reduce((acc, cur) => {
return acc.concat(Array.isArray(cur) && deep ? flatReduce(cur, deep) : cur);
}, []);
};
console.log(flatReduce([1, 2, [3], [4, [5]]], false)); // => 1,2,3,4,[5]
console.log(flatReduce([1, 2, [3], [4, [5, [6, 7, 8]]]], true)); // => 1,2,3,4,5,6,7,8
以下代码将压平深度嵌套的数组:
/**
* [Function to flatten deeply nested array]
* @param {[type]} arr [The array to be flattened]
* @param {[type]} flattenedArr [The flattened array]
* @return {[type]} [The flattened array]
*/
function flattenDeepArray(arr, flattenedArr) {
let length = arr.length;
for(let i = 0; i < length; i++) {
if(Array.isArray(arr[i])) {
flattenDeepArray(arr[i], flattenedArr);
} else {
flattenedArr.push(arr[i]);
}
}
return flattenedArr;
}
let arr = [1, 2, [3, 4, 5], [6, 7]];
console.log(arr, '=>', flattenDeepArray(arr, [])); // [ 1, 2, [ 3, 4, 5 ], [ 6, 7 ] ] '=>' [ 1, 2, 3, 4, 5, 6, 7 ]
arr = [1, 2, [3, 4], [5, 6, [7, 8, [9, 10]]]];
console.log(arr, '=>', flattenDeepArray(arr, [])); // [ 1, 2, [ 3, 4 ], [ 5, 6, [ 7, 8, [Object] ] ] ] '=>' [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]