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JavaScript: Check whether a given value is an valid url or not

JavaScript validation with regular expression: Exercise-9 with Solution

Write a JavaScript function to check whether a given value is a valid URL or not.

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript function to check whether a given value is an url or not</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function is_url(str)
{
  regexp =  /^(?:(?:https?|ftp):\/\/)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/\S*)?$/;
        if (regexp.test(str))
        {
          return true;
        }
        else
        {
          return false;
        }
}

console.log(is_url("http://www.example.com"));
console.log(is_url("https://www.example.com"));
console.log(is_url("www.example.com"));

Sample Output:

true
true
true

Flowchart:

Flowchart: JavaScript- Check whether a given value is an valid url or not

Live Demo:

See the Pen javascript-regexp-exercise-8 by w3resource (@w3resource) on CodePen.


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JavaScript: Tips of the Day

defineProperty method

const person = { name: 'Owen' };

Object.defineProperty(person, 'age', { value: 21 });

console.log(person);
console.log(Object.keys(person));

With the defineProperty method, we can add new properties to an object, or modify existing ones. When we add a property to an object using the defineProperty method, they are by default not enumerable. The Object.keys method returns all enumerable property names from an object, in this case only "name".
Properties added using the defineProperty method are immutable by default. You can override this behavior using the writable, configurable and enumerable properties. This way, the defineProperty method gives you a lot more control over the properties you're adding to an object.

Ref: https://bit.ly/323Y0P6

 

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