[英]How to add an element to an array inside an array in JS ES6?
For example, I know I can use spread operator to add an element to an array in ES6.例如,我知道我可以使用扩展运算符在 ES6 中将元素添加到数组中。
const arr = ["a","b"]
const newArr = [...arr, "c"]
that I get我得到
["a","b","c"]
But how to implement this in an nested array, like但是如何在嵌套数组中实现这一点,比如
const arr = [["a","b"], ["d"]]
I want to get我想得到
newArr1 = [["a","b","c"], ["d"]]
and和
newArr2 = [["a","b"],["d","c"]]
Perhaps we can use也许我们可以使用
[[...arr[0], 'c'], [...arr[1]]]
but what if但如果
const arr = [["a","b"], ["d"],["e"]]
and I still want我仍然想要
[["a","b","c"], ["d"],["e"]]
is there a common way?
You can simply use the array index or use findIndex and find methods, in case you want to remove not based on the index您可以简单地使用数组索引或使用 findIndex 和 find 方法,以防您不基于索引删除
const arr = [[a,b], [d]]
arr[1].push(c)
//arr = [[a,b], [c,d]]
const array = [['a', 'b'], ['d']]
const arrayIndex = array.findIndex(item => item.find(i => i === 'd'))
if (arrayIndex !== -1) {
const oldArray = array.find(item => item.find(i => i === 'd'))
const newArray = [...oldArray, 'c']
array[arrayIndex] = newArray
}
console.log(array);
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