在嵌套对象数组中查找对象

Question

const inventory = [
  { name: { vegetable: 'carrot' }, quantity: 2 },
  { name: { meat: 'pork' }, quantity: 0 },
  { name: { fruit: 'cherries' }, quantity: 5 },
];

const result = inventory.find(name => name === { fruit: 'cherries' });
console.log(result);

I have an array of nested objects and I'm trying to find out if there is one including the { fruit: 'cherries' } object but I get undefined as a result.

So I guess you can't pass an object as a search parameter?

Answer 1

You need to write full path to the object and access to object through . sign:

const result = inventory.find(name => name.name.fruit === 'cherries');

An example:

 const inventory = [ { name: { vegetable: 'carrot' }, quantity: 2 }, { name: { meat: 'pork' }, quantity: 0 }, { name: { fruit: 'cherries' }, quantity: 5 }, ]; const result = inventory.find(name => name.name.fruit === 'cherries'); console.log(result);

It will be better seen in debugger what there is actual path to your properties of object:

const result = inventory.find(name => {
    if(name.name.fruit === 'cherries')
        return name;
    return;
});
console.log(result);

Answer 2

You can't compare objects because they have different references . One way could be using destructuring and just simply access the fruit property in order to compare it with a given value .

 const inventory = [ { name: { vegetable: 'carrot' }, quantity: 2 }, { name: { meat: 'pork' }, quantity: 0 }, { name: { fruit: 'cherries' }, quantity: 5 }, ]; const result = inventory.find(({name}) => name.fruit == "cherries"); console.log(result);

Answer 3

Please explore Sbtree module or TyrDb module (TyrDb is a wrapper on top of Sbtree with abstracted API). These libraries let you search nested element.

Answer 4

Thanks for all the suggestions. I think I found a solution to my problem.

I used array.map to create a new array consisting of only the name objects . Then I used JSON.stringify on selectedOption and on the elements in the new array to find a match and/or index.

There is probably a better way of doing it but this is working OK. Feel free to point out any potential flaws in my approach.

 const selectedOption = {fruit_red: "cherries", fruit_green: "kiwi"} const inventory = [ { name: { vegetable: 'carrot' }, quantity: 2 }, { name: { meat: 'pork' }, quantity: 0 }, { name: { fruit_red: 'cherries', fruit_green: 'kiwi' }, quantity: 5 }, { name: { fruit_red: 'cherries', fruit_green: 'apple' }, quantity: 3 }, ]; const names = inventory.map(item => item.name) const resultIndex = names.findIndex(name => JSON.stringify(name) === JSON.stringify(selectedOption)); console.log(resultIndex) const result = names.find(name => JSON.stringify(name) === JSON.stringify(selectedOption)); console.log(result) console.log(inventory[resultIndex])