How to check a date is valid or not using JavaScript ?
Given a date object and the task is to check the given date is valid or not using JavaScript. There are two methods to solve this problem which are discussed below:
Approach 1:
- Store the date object in a variable.
- If the date is valid then the getTime() will always be equal to itself.
- If the date is Invalid then the getTime() will return NaN which is not equal to itself.
- The isValid() function is used to check the getTime() method is equal to itself or not.
Example 1: This example implements the above approach.
html
<!DOCTYPE HTML><html> <head> <title> How to check a date is valid or not using JavaScript ? </title></head> <body style = "text-align:center;"> <h1 style = "color:green;" > GeeksForGeeks </h1> <p id = "GFG_UP" style = "font-size: 15px; font-weight: bold;"> </p> <button onclick = "GFG_Fun()"> Click Here </button> <p id = "GFG_DOWN" style = "color:green; font-size: 20px; font-weight: bold;"> </p> <script> var up = document.getElementById('GFG_UP'); var down = document.getElementById('GFG_DOWN'); var d = new Date("2012/2/30"); up.innerHTML = "Click on the button to check" + " validity of data.<br>"; Date.prototype.isValid = function () { // If the date object is invalid it // will return 'NaN' on getTime() // and NaN is never equal to itself. return this.getTime() === this.getTime(); }; function GFG_Fun() { down.innerHTML = d.isValid(); } </script></body> </html> |
Output:
Check a date is valid or not
Approach 2:
- Store the date object into a variable d.
- Check if the variable d is created by Date object or not by using Object.prototype.toString.call(d) method.
- If the date is valid then the getTime() method will always be equal to itself.
- If the date is Invalid then the getTime() method will return NaN which is not equal to itself.
- In this example, isValid() method is checking if the getTime() is equal to itself or not.
Example 2: This example implements the above approach.
html
<!DOCTYPE HTML><html> <head> <title> How to check a date is valid or not using JavaScript ? </title></head> <body style = "text-align:center;"> <h1 style = "color:green;" > GeeksForGeeks </h1> <p id = "GFG_UP" style ="font-size: 15px; font-weight: bold;"> </p> <button onclick = "GFG_Fun()"> Click Here </button> <p id = "GFG_DOWN" style ="color:green; font-size: 20px; font-weight: bold;"> </p> <script> var up = document.getElementById('GFG_UP'); var down = document.getElementById('GFG_DOWN'); var d = new Date("This is not date."); up.innerHTML = "Click on the button to check " + "validity of data.<br>"; function GFG_Fun() { if (Object.prototype.toString.call(d) === "[object Date]") { if (isNaN(d.getTime())) { down.innerHTML = "Invalid Date."; } else { down.innerHTML = "Valid Date."; } } } </script></body> </html> |
Output:
Check a date is valid or not
JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript Examples.
Please Login to comment...