How do I map thorough the entire array which contains other objects and arrays as well in React?-CodePudding

I have created a JavaScript array that contains some other objects. the subobjects contain arrays. Now I want to iterate through the entire parent object in React. I use the following approach but it does not work:

Array

const users =[
    {
        id:1,
        username: "user1",
        path: "/user",
        listItems: {lists:["list-1", "List-2", "List-3", "List-4", "List-5"], path: ["/list-1", "/List-2", "/List-3", "/List-4", "/List-5"]}
    },
    {
        id:2,
        username: "user2",
        path: "/user2",
        listItems: {lists:["list-1", "List-2", "List-3", "List-4", "List-5"], path: ["/list-1", "/List-2", "/List-3", "/List-4", "/List-5"]}
    },
    {
        id:3,
        username: "user3",
        path: "/user3",
        listItems: {lists:["list-1", "List-2", "List-3", "List-4", "List-5"], path: ["/list-1", "/List-2", "/List-3", "/List-4", "/List-5"]}
    }
]

usersInfo component

export default function usersInfo(props){
const users = props.users;
return(
<div className="container">
{users.map((item)=>{
    return(
        <section className="user">
        <h1>{item.username}</h1>
        <p>{item.path}</p>
        <Link href={item.path}>Visit</Link>
        <p>Users lists</p>
        <ul>
        {item.listItems.map((topic)=>{
            <Link href={topic.path}<li>{topic.lists}</li>
        })}
        </ul>
        </section>  
)})}

</div>
)}

Using usersInfo coponent in React:

<usersInfo users = {users}/>

Everything works fine. But I get an issue when trying to map through the listItems object which contains two arrays lists and path. How do I solve this?

I expect the output like this:

CodePudding user response：

you missing that,

replace this, this is wrong .map() wont work here, as listItems its json object, you need change this code,

    <ul>
    {item.listItems.map((topic)=>{
        <Link href={topic.path}<li>{topic.lists}</li>
    })}
    </ul>

replace to this, this will work

<ul>
{
  item.listItems.lists.map((list)=>{
    <li>{list}</li>
  })
  item.listItems.path.map((topic)=>{
    <Link href={topic.path}<li>{topic.lists}</li>
  })
}
</ul>

CodePudding user response：

You are trying to use map method on an Object. map is a Array method and not available for object. Object.keys.map must solve this.

export default function usersInfo(props){
const users = props.users;
return(
<div className="container">
{users.map((item)=>{
    return(
        <section className="user">
        <h1>{item.username}</h1>
        <p>{item.path}</p>
        <Link href={item.path}>Visit</Link>
        <p>Users lists</p>
        <ul>
        {Object.keys(item.listItems)[0].map((list, i)=>{
          
            <Link href={item.listItems.path[i]}<li>{list}</li>
        })}
        </ul>
        </section>  
)})}

</div>
)}

CodePudding user response：

If it's guaranteed that lists and paths indices match and you want your <li> elements to contain the links, you can simply do:

<ul>
    {item.listItems.lists.map((listItem, listIndex)=>{
       return(<li><Link href={item.listItems.path[listIndex]}>{listItem}</Link></li>);
    })}
</ul>