JavaScript 6 中是否有允许映射多个数组的功能?
像拉链一样的东西:
var myFn = function (a, b) { console.log(a, b);}
var arr1 = ['a', 'b', 'c'];
var arr2 = [1, 2, 3];
arr1.map(myFn, arr2); // imaginary syntax.
// prints :
// a 1
// b 2
// c 3
正如另一个答案指出的那样,这通常被称为
zip
。它可以实现为:
let zipped = arr1.map((x, i) => [x, arr2[i]]);
或者作为一个函数,基本上:
let zip = (a1, a2) => a1.map((x, i) => [x, a2[i]]);
这会让你这样做:
zip(["a","b","c"], [1,2,3]); // ["a", 1], ["b", 2], ["c", 3]
您还可以使用
reduce
来获得所需的结果:
var arr1 = ['a', 'b', 'c'];
var arr2 = [1, 2, 3];
arr1.reduce((acc, current, index) => {
console.log(current, arr2[index])
return [...acc, current, arr2[index]]
}, [])
// a 1
// b 2
// c 3
// returns ["a", 1, "b", 2, "c", 3]
参考@Onaracs的答案并进行编辑。
const arr1 = ['a', 'b', 'c']
const arr2 = [1, 2, 3]
const arr3 = arr1.reduce((acc, current, index) => {
return [...acc, [current, arr2[index]]]
}, [])
console.log(arr3)
聚会迟到了,但这是我的解决方案。
// Custom zip
const zip = function (N, callback) {
if (this.length === 0 || N.length === 0 || this.length !== N.length) {
console.error(`Arrays are of different lengths or empty.`);
return;
}
for (let i = 0; i < this.length; i++) {
callback(this[i], N[i], i, this, N);
}
};
// Custom zipMap
const zipMap = function (N, callback) {
if (this.length === 0 || N.length === 0 || this.length !== N.length) {
console.error(`Arrays are of different lengths or empty.`);
return;
}
const results = [];
for (let i = 0; i < this.length; i++) {
results.push(callback(this[i], N[i], i, this, N));
}
return results;
};
// Basic Usage:
Let numberArr = [1,2,3];
Let stringArr = ['a','b','c'];
// Add zip function to array as a property.
numberArr.zip = zip;
//or
numberArr.zipMap = zipMap;
const callback = function(itemA, itemB, index, ArrayA, ArrayB){
console.log(itemA + itemB)
}
numberArr.zip(stringArr, callback);
// prints :
// a 1
// b 2
// c 3
您还可以将函数添加到
Array.prototype
,但我不建议这样做,除非它只在您的代码库中使用。这篇post解释了为什么应该避免它。
//Use with caution
Object.defineProperty(Array.prototype, 'zip', {
value: zip
});
Object.defineProperty(Array.prototype, 'zipMap', {
value: zipMap
});