How to validate TextBox in JavaScript on button click?
As a web developer, it is important to validate user inputs before sending them to the server-side for processing. This is especially true when working with forms that contain text boxes.
In this article, we will discuss how you can validate TextBox in JavaScript on button click.
How to validate TextBox in JavaScript#
The first step in validating a TextBox using JavaScript is to assign an event handler function (such as "onclick") to the submit button of your form element.
The purpose of this function will be twofold:
- To check whether or not any data has been entered into the text box.
- If so, then perform any additional validation logic necessary for that particular field type.
For example:
In the above example, we initialize a variable called textBoxValue and assigns it the value of the text box with the ID myInput. The trim() method is called on this value to remove any leading or trailing white space.
The second line checks whether the value of textBoxValue is equal to an empty string. If it is, an alert message is displayed saying "Please enter your name!" and the function returns false. Otherwise, an alert message is displayed saying "Form is submitted!" and the function returns true.
