I have an array of objects. I would like to map this array of objects. I know how to map an array, but can't figure out how to map an array of objects. Here is what I have done so far :
The array of objects I want to map :
const theData = [
{
name: 'Sam',
email: '[email protected]'
},
{
name: 'Ash',
email: '[email protected]'
}
]
My component :
class ContactData extends Component {
render() {
//works for array
const renData = this.props.dataA.map((data, idx) => {
return <p key={idx}>{data}</p>
});
//doesn't work for array of objects
const renObjData = this.props.data.map(function(data, idx) {
return <p key={idx}>{data}</p>
});
return (
<div>
//works
{rennData}
<p>object</p>
//doesn't work
{renObjData}
</div>
)
}
}
ContactData.PropTypes = {
data: PropTypes.arrayOf(
PropTypes.obj
),
dataA: PropTypes.array
}
ContactData.defaultProps = {
data: theData,
dataA: dataArray
}
What am I missing ?
The answer is, you use Array. map() in your component and return JSX elements inside the Array. map() callback function to render the UI.
The syntax for the map() method is as follows: arr. map(function(element, index, array){ }, this); The callback function() is called on each array element, and the map() method always passes the current element , the index of the current element, and the whole array object to it.
To map through an object's value in React: Use the Object. values() method to get an array of the object's values. Call the map() method on the array of values.
We will use the map function to access each object from the array. The map() method in JavaScript creates an array by calling a specific function on each element present in the parent array. It is a non-mutating method.
What you need is to map your array of objects and remember that every item will be an object, so that you will use for instance dot notation to take the values of the object.
In your component
[
{
name: 'Sam',
email: '[email protected]'
},
{
name: 'Ash',
email: '[email protected]'
}
].map((anObjectMapped, index) => {
return (
<p key={`${anObjectMapped.name}_{anObjectMapped.email}`}>
{anObjectMapped.name} - {anObjectMapped.email}
</p>
);
})
And remember when you put an array of jsx it has a different meaning and you can not just put object in your render method as you can put an array.
Take a look at my answer at mapping an array to jsx
@FurkanO has provided the right approach. Though to go for a more cleaner approach (es6 way) you can do something like this
[{
name: 'Sam',
email: '[email protected]'
},
{
name: 'Ash',
email: '[email protected]'
}
].map( ( {name, email} ) => {
return <p key={email}>{name} - {email}</p>
})
Cheers!
I think you want to print the name of the person or both the name and email :
const renObjData = this.props.data.map(function(data, idx) {
return <p key={idx}>{data.name}</p>;
});
or :
const renObjData = this.props.data.map(function(data, idx) {
return ([
<p key={idx}>{data.name}</p>,
<p key={idx}>{data.email}</p>,
]);
});
you must put object in your JSX, It`s easy way to do this just see my simple code here:
const link = [
{
name: "Cold Drink",
link: "/coldDrink"
},
{
name: "Hot Drink",
link: "/HotDrink"
},
{
name: "chease Cake",
link: "/CheaseCake"
}
];
and you must map this array in your code with simple object see this code :
const links = (this.props.link);
{links.map((item, i) => (
<li key={i}>
<Link to={item.link}>{item.name}</Link>
</li>
))}
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