useEffect(() => {
const url = "https://api.adviceslip.com/advice";
const fetchData = async () => {
try {
const response = await fetch(url);
const json = await response.json();
console.log(json);
} catch (error) {
console.log("error", error);
}
};
fetchData();
}, []);//for functional components//
function MyComponent() {
const [error, setError] = useState(null);
const [isLoaded, setIsLoaded] = useState(false);
const [items, setItems] = useState([]);
// Note: the empty deps array [] means
// this useEffect will run once
// similar to componentDidMount()
useEffect(() => {
fetch("https://api.example.com/items")
.then(res => res.json())
.then(
(result) => {
setIsLoaded(true);
setItems(result);
},
// Note: it's important to handle errors here
// instead of a catch() block so that we don't swallow
// exceptions from actual bugs in components.
(error) => {
setIsLoaded(true);
setError(error);
}
)
}, [])
if (error) {
return <div>Error: {error.message}</div>;
} else if (!isLoaded) {
return <div>Loading...</div>;
} else {
return (
<ul>
{items.map(item => (
<li key={item.id}>
{item.name} {item.price}
</li>
))}
</ul>
);
}
}/* React get method. */
componentWillMount(){
fetch('/getcurrencylist',
{
/*
headers: {
'Content-Type': 'application/json',
'Accept':'application/json'
},
*/
method: "get",
dataType: 'json',
})
.then((res) => res.json())
.then((data) => {
var currencyList = [];
for(var i=0; i< data.length; i++){
var currency = data[i];
currencyList.push(currency);
}
console.log(currencyList);
this.setState({currencyList})
console.log(this.state.currencyList);
})
.catch(err => console.log(err))
}// mycomponent.js
import React, { useEffect, useState} from 'react';
import axios from 'axios';
const MyComponent = () => {
const [loading, setLoading] = useState(true);
const [data, setData] = useState([])
useEffect(() => {
const fetchData = async () =>{
setLoading(true);
try {
const {data: response} = await axios.get('/stuff/to/fetch');
setData(response);
} catch (error) {
console.error(error.message);
}
setLoading(false);
}
fetchData();
}, []);
return (
<div>
{loading && <div>Loading</div>}
{!loading && (
<div>
<h2>Doing stuff with data</h2>
{data.map(item => (<span>{item.name}</span>))}
</div>
)}
</div>
)
}
export default MyComponent;//for calsses components//
class MyComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
error: null,
isLoaded: false,
items: []
};
}
componentDidMount() {
fetch("https://api.example.com/items")
.then(res => res.json())
.then(
(result) => {
this.setState({
isLoaded: true,
items: result.items
});
},
// Note: it's important to handle errors here
// instead of a catch() block so that we don't swallow
// exceptions from actual bugs in components.
(error) => {
this.setState({
isLoaded: true,
error
});
}
)
}
render() {
const { error, isLoaded, items } = this.state;
if (error) {
return <div>Error: {error.message}</div>;
} else if (!isLoaded) {
return <div>Loading...</div>;
} else {
return (
<ul>
{items.map(item => (
<li key={item.id}>
{item.name} {item.price}
</li>
))}
</ul>
);
}
}
}