javascript - 如何在嵌套数组上使用 find() 方法？

Question

在此示例中，您可以看到 find 方法在此数组中工作正常:

var inventory = [
    {name: 'apples', quantity: 2},
    {name: 'bananas', quantity: 0},
    {name: 'cherries', quantity: 5}
];


console.log(inventory.find(fruit => fruit.name === 'cherries')); 
// { name: 'cherries', quantity: 5 }

一旦我再添加一个级别并尝试在其中查找项目，它就是找不到它，它显示未定义:

var inventory = [
    {name: 'apples', quantity: 2},
    {name: 'bananas', quantity: 0},
    {name: 'cherries', quantity: 5, type: [
       {name: 'rainier', quantity: 3},
       {name: 'bing', quantity: 2}
     ]}
];


console.log(inventory.find(fruit => fruit.name === 'bing')); 
// undefined
// should be: { name: 'bing', quantity: 2 }

所以我想还有其他方法可以做到这一点，但我不知道也找不到任何东西。

Answer 1

您的代码不允许使用可选的 type 数组。假设您想进行深度优先搜索，您可以将回调设为命名函数并递归使用它，请参阅评论:

var inventory = [
    {name: 'apples', quantity: 2},
    {name: 'bananas', quantity: 0},
    {name: 'cherries', quantity: 5, type: [
       {name: 'rainier', quantity: 3},
       {name: 'bing', quantity: 2}
    ]}
];

// Define the function
function find(array, name) {
    // Loop the entries at this level
    for (const entry of array) {
        // If we found it, return it
        if (entry.name === name) {
            return entry;
        }
        // If not but there's a type array, recursively search it
        if (Array.isArray(entry.type)) {
            const found = find(entry.type, name);
            if (found) {
                // Recursive search found it, return it
                return found;
            }
        }
    }
    // If execution falls off the end, it's effectively `return undefined;`
}
console.log(find(inventory, 'bing'));