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JavaScript: Get the extension of a filename

JavaScript Basic: Exercise-14 with Solution

Write a JavaScript exercise to get the extension of a filename.

Pictorial Presentation:

JavaScript: Get the extension of a filename

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>The extension of a filename.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

filename = "system.php"
console.log(filename.split('.').pop());
filename = "abc.js"
console.log(filename.split('.').pop());

Sample Output:

php
js

ES6 Version:

filename = "system.php"
console.log(filename.split('.').pop());
filename = "abc.js"
console.log(filename.split('.').pop());

Live Demo:

See the Pen JavaScript: Extension of a filename - basic-ex-14 by w3resource (@w3resource) on CodePen.


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Next: Write a JavaScript program to get the difference between a given number and 13, if the number is greater than 13 return double the absolute difference.

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JavaScript: Tips of the Day

Parameter's value

function getItems(fruitList, ...args, favoriteFruit) {
  return [...fruitList, ...args, favoriteFruit]
}

getItems(["banana", "apple"], "pear", "orange")

...args is a rest parameter. The rest parameter's value is an array containing all remaining arguments, and can only be the last parameter! In this example, the rest parameter was the second parameter. This is not possible, and will throw a syntax error.

function getItems(fruitList, favoriteFruit, ...args) {
  return [...fruitList, ...args, favoriteFruit];
}


getItems(['banana', 'apple'], 'pear', 'orange');
The above example works. This returns the array [ 'banana', 'apple', 'orange', 'pear' ].

Ref: https://bit.ly/3jFRBje