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Explain the callback Promise.finally in JavaScript
The promise.finally() calls the callback function whether a promise has been fulfilled or rejected. This helps us to do something once the promise has been rejected or resolved.
Following is the code for Promise.finally() in JavaScript −
Example
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
body {
font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
.result {
font-size: 20px;
font-weight: 500;
}
</style>
</head>
<body>
<h1>Promise.finally in JavaScript</h1>
<div style="color: green;" class="result"></div>
<button class="btn">CLICK HERE</button>
<h3>
Click on the above button to know when the promise finishes
</h3>
<script>
let btnEle = document.querySelector(".btn");
let resEle = document.querySelector(".result");
const yearRegex = /(?\d{4})/g;
btnEle.addEventListener("click", () => {
fetch("https://jsonplaceholder.typicode.com/users")
.then((Response) => Response.json())
.then((res) => res)
.catch((err) => alert("error occured"))
.finally(() => (resEle.innerHTML = "Promise is finished"));
});
</script>
</body>
</html>
Output
The above code will produce the following output −
On clicking the ‘CLICK HERE’ button and waiting some seconds −
Updated on: 2020-07-15T13:06:56+05:30
212 Views
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