I have a question about working with the find method. I have a task - I need to go through the array and find a match with a specific string. But at the same time there is a condition that this string can be inside one of the objects already in its child array. I make an if construct in my function to check this when passing through the array, but it does not work out as I expected. Tell me, please, where I went wrong.
P.S. I write more correctly. If the array object "newList" has "items" , then you need to look for comparison not in the object, but in its "items" array among "role" . If "items" does not exist for the object, then we look for a match in this object among "role"
const newList = [
{
role: "role111",
title: "title1",
},
{
role: "role222",
title: "title2",
},
{
role: "role333",
title: "title3",
},
{
role: "role444",
title: "title4",
items: [{
role: "role555",
title: "title5",
}, {
role: "role666",
title: "title6",
}, {
role: "role777",
title: "title7",
},]
},
{
role: "role888",
title: "title8",
},
];
const url = "role7";
export const findAfterRefresh = (list, url) =>
list.find((item) => {
if (item.items && item.items?.length > 0) {
return item.items.find((childrenITem) => childrenITem.role.includes(url));
}
return item.role.includes(url);
});
;
findAfterRefresh(newList, url);
Your solution was close, but if you call find on newList, it can only ever return one of the elements of newList, it can't return an element from the items array of one of those elements. That plus the fact you want the role value, not the element itself, makes the find method not a good match for your current data structure (but keep reading; if you really want to use find, there's a way).
Instead, a simple loop with recursion does the job:
/*export*/ const findAfterRefresh = (list, url) => {
for (const item of list) {
if (item.role?.includes(url)) {
return item.role;
}
if (item.items?.length) {
const childRole = findAfterRefresh(item.items, url);
if (childRole) {
return childRole;
}
}
}
};
Here's a version with explanatory comments:
/*export*/ const findAfterRefresh = (list, url) => {
// Loop the given list...
for (const item of list) {
// ...check this item's role
// (Remove v-- this `?` if `role` will always be there)
if (item.role?.includes(url)) {
return item.role;
}
// If this item has child items, check them
if (item.items?.length) {
// Search child items using recursion
const childRole = findAfterRefresh(item.items, url);
if (childRole) {
// Found it, return it
return childRole;
}
// Didn't find it, keep looping
}
}
};
Live Example:
const newList = [
{
role: "role1",
title: "title1",
},
{
role: "role2",
title: "title2",
},
{
role: "role3",
title: "title3",
},
{
role: "role4",
title: "title4",
items: [
{
role: "role5",
title: "title5",
},
{
role: "role6",
title: "title6",
},
{
role: "role7plusotherstuff",
title: "title7",
},
],
},
];
/*export*/ const findAfterRefresh = (list, url) => {
// Loop the given list...
for (const item of list) {
// ...check this item's role
// (Remove v-- this `?` if `role` will always be there)
if (item.role?.includes(url)) {
return item.role;
}
// If this item has child items, check them
if (item.items?.length) {
// Search child items using recursion
const childRole = findAfterRefresh(item.items, url);
if (childRole) {
// Found it, return it
return childRole;
}
// Didn't find it, keep looping
}
}
};
console.log("Searching for 'role7'");
console.log(findAfterRefresh(newList, "role7"));
console.log("Searching for 'role2'");
console.log(findAfterRefresh(newList, "role2"));
Note: I added a bit to the role containing role7 so you could see that the code returns the full role, not just the bit in url.
But if you really want to use find, you can do it by first creating a flat array of roles:
// Creates a new array of `role` values (the array may also contain
// `undefined`, if the `role` property of any element or child element is
// `undefined`)
const flattenRoles = (list) =>
(list ?? []).flatMap((item) => [item.role, ...flattenRoles(item.items)]);
/*export*/ const findAfterRefresh = (list, url) => {
return flattenRoles(list).find((role) => role?.includes(url));
};
That code's a big shorter, but note that it creates a number of temporary arrays, and it always works its way through the full list before looking for roles, whereas the earlier version stops looking as soon as it's found a matching role. That's unlikely to be a problem if newList is of a reasonable size, but it's worth keeping in mind. (I'd probably use the earlier version, not this.)
Here's that in action:
const newList = [
{
role: "role1",
title: "title1",
},
{
role: "role2",
title: "title2",
},
{
role: "role3",
title: "title3",
},
{
role: "role4",
title: "title4",
items: [
{
role: "role5",
title: "title5",
},
{
role: "role6",
title: "title6",
},
{
role: "role7plusotherstuff",
title: "title7",
},
],
},
];
// Creates a new array of `role` values (the array may also contain
// `undefined`, if the `role` property of any element or child element is
// `undefined`)
const flattenRoles = (list) =>
(list ?? []).flatMap((item) => [item.role, ...flattenRoles(item.items)]);
/*export*/ const findAfterRefresh = (list, url) => {
return flattenRoles(list).find((role) => role?.includes(url));
};
console.log("Searching for 'role7'");
console.log(findAfterRefresh(newList, "role7"));
console.log("Searching for 'role2'");
console.log(findAfterRefresh(newList, "role2"));
In a comment you've asked:
ESLint: iterators/generators require regenerator-runtime, which is too heavyweight for this guide to allow them. Separately, loops should be avoided in favor of array iterations.(no-restricted-syntax)
...how much do you think eslnit is right in this case?
That's up to you. If your target environment is ES2015+, there's no need for regenerator-runtime. As far as I know, there are no major pre-ES2015+ environments (IE11 is obsolete and discontinued). But if you need to support it and want to avoid regenerator-runtime, you can replace the for-of loop with some and assigning to a closed-over variable:
const newList = [
{
role: "role1",
title: "title1",
},
{
role: "role2",
title: "title2",
},
{
role: "role3",
title: "title3",
},
{
role: "role4",
title: "title4",
items: [
{
role: "role5",
title: "title5",
},
{
role: "role6",
title: "title6",
},
{
role: "role7plusotherstuff",
title: "title7",
},
],
},
];
/*export*/ const findAfterRefresh = (list, url) => {
// Loop the given list...
let role;
list.some((item) => {
// ...check this item's role
// (Remove v-- this `?` if `role` will always be there)
if (item.role?.includes(url)) {
role = item.role;
return true;
}
// If this item has child items, check them
if (item.items?.length) {
// Search child items using recursion
const childRole = findAfterRefresh(item.items, url);
if (childRole) {
// Found it, return it
role = childRole;
return true;
}
// Didn't find it, keep looping
}
});
return role;
};
console.log("Searching for 'role7'");
console.log(findAfterRefresh(newList, "role7"));
console.log("Searching for 'role2'");
console.log(findAfterRefresh(newList, "role2"));
The return true; statements tell some that you're done, it can stop looping.
...and the error on childRole from typescript is TS7022: 'childRole' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
The TypeScript error is just because the code doesn't have type annotations, because it was a JavaScript question, not a TypeScript question. :-) If you add the appropriate type annotations, it'll be fine.
As per my understanding, You are trying to filtered out the newList with all the objects includes role7 string in role property either in main object or in the child array objects. If Yes, You have to use Array.filter() method instead of Array.find() as it will only returns the first element in the provided array that satisfies the provided testing function.
Live Demo :
const newList = [
{
role: "role111",
title: "title1",
},
{
role: "role777",
title: "title2",
},
{
role: "role333",
title: "title3",
},
{
role: "role444",
title: "title4",
items: [{
role: "role555",
title: "title5",
}, {
role: "role666",
title: "title6",
}, {
role: "role777",
title: "title7",
},]
},
{
role: "role888",
title: "title8",
},
];
const url = "role7";
const findAfterRefresh = (list, url) =>
list.filter((item) => {
return (item.role.includes(url)) ? item :
item.items = item.items?.filter((childrenITem) => childrenITem.role.includes(url));
});
console.log(findAfterRefresh(newList, url));
After reading some of the other solutions I was able to refactor my code down a little bit. I decided to convert the raw array value into a 2d array, each nested array value would hold the role and item values.
I chose to do things this way so that the output of this function can still be used for any purpose regarding the roles and titles of these items. and to create an array which would be easy to iterate through.
const url = "role6";
const findAfterRefresh = (list) =>{
let foundData = []
list.find((item) => {
foundData.push([item.role, item.title]);
if (item.items !== undefined) {
item.items.find((item) => {
foundData.push([item.role, item.title]);
})
}
});
return foundData
}
for(let v in findAfterRefresh(newList) ){
if (findAfterRefresh(newList)[v].includes(url)) {
console.log(findAfterRefresh(newList)[v].includes(url)); break
}
}
//output of findAfterRefresh: [[role1,title1],[role2,title2][... etc
//ouput of the for loop at the bottom: true...
Ok I got to it.
Edit: I didn't read the title carefully, the code at the bottom is with for instead of "find" I hope it's not a problem
const newList = [
{
role: "role1",
title: "title1",
},
{
role: "role2",
title: "title2",
},
{
role: "role3",
title: "title3",
},
{
role: "role4",
title: "title4",
items: [{
role: "role5",
title: "title5",
}, {
role: "role6",
title: "title6",
}, {
role: "role7",
title: "title7",
},]
}
];
const url = "role2";
const findAfterRefresh = (list, url) => {
for(const singleItem of Object.values(list)) {
if(singleItem.items && singleItem.items?.length > 0) {
return singleItem.items.find(child => child.role === url);
};
if(!singleItem.role.includes(url)) {
continue;
};
return singleItem;
}
};
findAfterRefresh(newList, url);
I can't google the right solution for this for about an hour straight,
So I'm getting a response from the API that looks like this:
[
{
"Name": "name1",
"Title": "Name One",
"Children": [
{
"Name": "Name 1.1",
"Title": "Name one point one"
},
]
And I need it to fit this kind of "mold" for the data to fit in:
{
title: 'Name One',
value: 'name1',
key: '1',
children: [
{
title: 'Name one point one',
value: 'Name 1.1',
key: 'key1',
},
I am trying to achieve this using a foreach but It's not working as intended because I need to do this all in one instance of a foreach.
Here's what I gave a go to(vue2):
created() {
getData().then(response => {
const formattedResponse = []
response.forEach((el, key) => {
formattedResponse.title = response.Title
formattedResponse.name = response.Name
formattedResponse.children = response.Children
})
})
Use map over the main array and use destructuring assignment to extract the properties by key, and relabel them, and then do exactly the same with the children array. Then return the updated array of objects.
const data=[{Name:"name1",Title:"Name One",Children:[{Name:"Name 1.1",Title:"Name one point one"}]},{Name:"name2",Title:"Name Two",Children:[{Name:"Name 1.2",Title:"Name one point two"}]}];
const result = data.map((obj, key) => {
const { Title: title, Name: value } = obj;
const children = obj.Children.map(obj => {
const { Title: title, Name: value } = obj;
return { title, value, key: (key + 1).toString() };
});
return { title, value, children };
});
console.log(result);
Your API response is JSON. All you need to do is:
var resp=JSON.parse(API response);
I'm trying to return a new array of objects from the nested properties of another object. This is my current object:
const teams = {
GRYFFINDOR: {
display: 'Gryffindor',
channel: ['#team-gryffindor'],
ui: 'lion',
},
HUFFLEPLUFF: {
display: 'Hufflepuff',
channel: ['#team-hufflepuff'],
ui: '', // empty string on purpose
},
SLYTHERIN: {
display: 'Slytherin',
channel: ['#team-slytherin'],
ui: 'snake',
},
}
Now, I'm trying to return an array of objects like so:
[
{ value: 'lion' },
{ value: '' },
{ value: 'snake' },
]
This is what I have tried:
const teamsUI = [Object.keys(teams).reduce((carry, item) => {
return {...carry, ...{ ['value']: teams[item].ui }}
}, {})];;
However, I get this:
console.log(teamsUI); // returns [ { value: 'snake' }]
What am I doing wrong?
You could do like this:
const teams = {
GRYFFINDOR: {
display: 'Gryffindor',
channel: ['#team-gryffindor'],
ui: 'lion',
},
HUFFLEPLUFF: {
display: 'Hufflepuff',
channel: ['#team-hufflepuff'],
ui: '', // empty string on purpose
},
SLYTHERIN: {
display: 'Slytherin',
channel: ['#team-slytherin'],
ui: 'snake',
},
}
const result = Object.values(teams).map(({ ui }) => ({ value: ui }));
console.log(result);
Beside nested result structure, you could take the values and destructure the wanted property formapping.
const
teams = { GRYFFINDOR: { display: 'Gryffindor', channel: ['#team-gryffindor'], ui: 'lion' }, HUFFLEPLUFF: { display: 'Hufflepuff', channel: ['#team-hufflepuff'], ui: '' }, SLYTHERIN: { display: 'Slytherin', channel: ['#team-slytherin'], ui: 'snake' } },
result = Object.values(teams).map(({ ui: value }) => ({ value }));
console.log(result);
Here is the shortest way to achieve what you want
Object.keys(teams).map(t=>({value: teams[t].ui}))
Now what are you doing wrong?
Take a look at this part
Object.keys(teams).reduce((carry, item) => {
return {...carry, ...{ ['value']: teams[item].ui }}
}, {});
You're reducing your object to a single value with the same key called value. This means that the value of teams[item].ui of the current object in the reduce function will override the previous and hence you'll end up with the last object of that reduce function. You're finally wrapping this last object in an array which gives you what you have.
A better way to achieve that will be to do something like this
Object.keys(teams).reduce((carry, item, index)=>{
carry[index] = { value: teams[item].ui };
return carry;
}, []);
I am trying to update a nested value of an object using the spread operator. This is my first time using this and I believe I am pretty close to achieving my end goal but I just can't seem to figure out what I actually need to do next.
I have an array which is structured like this:
[
{
name: "Category 1",
posts: [
{
id: 1,
published: false,
category: "Category 1"
},
{
id: 2,
published: true,
category: "Category 1"
}
]
},
{
name: "Category 2",
posts: [
{
id: 3,
published: true,
category: "Category 2"
},
{
id: 4,
published: true,
category: "Category 2"
}
]
}
]
On the click of a button I am trying to update the published value, and as I am using React I need to set the state. So it got recommended to me that I update using the spread operator.
onPostClick(post) {
post.pubished = !post.published;
this.setState({...this.state.posts[post.category], post})
}
If I log out the result of {...this.state.posts[post.category], post} I can see that the published is getting added to the parent which forms:
{
name: "Category 1",
published: false,
posts: [
...
]
}
Obviously this isn't the intended result, I want it to update the actual object within the posts object.
I have tried to do something like this.setState({...this.state.posts[post.category].posts, post}) but I get a message that it is undefined.
You can't access your data with this.state.posts[post.category]. posts data in the objects of the array.
You can make a filter to find your category object in array and change its posts value.
onPostClick(post) {
//CLONE YOUR DATA
var postArray = this.state.posts;
//FIND YOUR CATEGORY OBJECT IN ARRAY
var categoryIndex = postArray.findIndex(function(obj){
return obj.name === post.category;
});
//FIND YOUR POST AND CHANGE PUBLISHED VALUE
postArray[categoryIndex].posts.forEach(function(item){
if (item.id === post.id) {
item.published = !item.published;
}
});
//SET TO STATE TO RERENDER
this.setState({ posts: postArray});
}
This should work if your name of the state is true.
just adding, we know there are many ways to succeed, maybe you also want to try this way too..
onPostClick = post => {
let published = this.state.data.map((item, i) => {
item.posts.map((item_post, i) => {
if (item_post.category === post.category) {
item_post.published = !post.published;
}
});
});
this.setState({ ...this.state.data, published });
};
I am having an error that my obj.push() and obj.concat() is not a function but I am not so sure why. Here is my code:
onSearch = () => {
var obj = {
product: [
{
field: "is_published",
filter_value: 1
},
{
field: "order_mode",
filter_array: [
"fcfs",
"purchase-order"
]
},
{
relationship: "store",
filter_object: {
field: "slug",
filter_value: "sample"
}
}
]
}
if (this.state.search !== "") {
obj.push(
{
field: "name",
text_search: this.state.search
}
)
}
var obj2 = {
taxonomies: [
[
{ field: "type",
filter_value: "seller"
},
{ field: "slug",
filter_value: "brand"
}
]
]
}
var conc = obj.concat(obj2);
var { getProductSearch } = this.props
getProductSearch(obj.concat(obj2))
}
product and taxonomies are stored in different variables but I need to pass them as one array to getProductSearch and for that, I need to use concat(). then I need to use push() because I want to add an object to the array obj. What am I doing wrong?
The simple answer is because you can't push onto an object. Push is used for arrays.
To make this work you could instead change your code to push onto the array in your object by doing.
obj.product.push(
{
field: "name",
text_search: this.state.search
}
)
If you are trying to make product dynamic where there are multiple products like [fruits, veggies, meat] then you could change it simply by doing
onSearch(productName)
obj[productName].push(
{
field: "name",
text_search: this.state.search
}
)
This would let you call onSearch(veggies) and push only to that array if you set it up that way.