這是一個陣列：
let arr = [{key: 1, value: "A", children: [{key: 2, value: "B"}]}]
我試圖用元素的序列數制作簡單的串列：
let list = [{key: 1, value: "A", "num": 1}, {key: 2, value: "B", "num": "1.1"}]
我的認識是：
private productsWithNumber(products: any[]) {
const arr = [];
products.forEach((p, index: number) => {
p['num'] = index 1;
if (p?.children) {
p.children.forEach((element, index) => {
element['num'] = `${p['num']}.${index 1}.`;
arr.push(element);
});
}
arr.push(p);
});
return arr;
}
結果我得到了錯誤的元素順序。如何簡化它？
uj5u.com熱心網友回復：
您當前正在遍歷所有專案，然后遍歷子項，添加子項，然后添加父項。
您可以簡單地先添加父級以獲得正確的順序：
private productsWithNumber(products: any[]) {
const arr = [];
products.forEach((p, index: number) => {
p['num'] = index 1;
arr.push(p); // <-- moved this line up
if (p?.children) {
p.children.forEach((element, index) => {
element['num'] = `${p['num']}.${index 1}.`;
arr.push(element);
});
}
});
return arr;
}
任意嵌套的解決方案：
當前解決方案僅適用于 1 級嵌套children。如果您希望它適用于任意嵌套級別，您可以使用recursion，例如：
type ArrayItem = {
children?: (ArrayItem | {})[]
}
const flattenChildrenArray = <T extends ArrayItem>(arr: T[], level: string | null = null): Omit<T, "children">[] => {
const tempArr: Omit<T, "children">[] = []
arr.forEach((item, index) => {
const {children, ...rest} = item;
const num = level ? `${level}.${index 1}` : `${index 1}`
tempArr.push({
...rest,
num,
})
if (children) {
const flattenedChildren = flattenChildrenArray(children, num) as Omit<T, "children">[]
tempArr.push(...flattenedChildren)
}
})
return tempArr;
}
在此處查看一個作業示例
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/506779.html
標籤：javascript