How to write alert function in javascript

A function can take multiple parameters separated by comma. These passed parameters can be captured inside the function and any manipulation can be done over those parameters. Knowing how to write your own functions will improve almost any JavaScript you create.

Example The function below should return the product of two numbers a and b: The most common way to define a function in JavaScript is by using the function keyword, followed by a unique function name, a list of parameters that might be emptyand a statement block surrounded by curly braces.

After the parentheses you need a pair of curly brackets. Now it takes two parameters. If the user clicks "Cancel", the box returns false. The basic structure of a homemade function A function definition starts with the word function.

When you call the alert function, JavaScript under stands it as a command to carry out some task, such as opening a window that has an OK button and a close button and putting some text in the window.

An Example of a Simple Function Figure shows you how the window-centering code in Figure looks rewritten as a web page containing a function. If the user clicks "Cancel" the box returns null.

So, functions that are going to return a value must use the return statement. Notice that the link calling the function X has the same form as a link that calls a built-in JavaScript function--the function name appears inside an onClick. The return Statement The return statement is used to specify the value that is returned from the function.

This is required if you want to return a value from a function. Next Page A function is a group of reusable code which can be called anywhere in your program. If the user clicks "OK" the box returns the input value. It defines a function that takes two parameters and concatenates them before returning the resultant in the calling program.

Example Try the following example. They allow you to call a set of JavaScript instructions the function just by using its name.A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses ().

Function names can contain letters, digits, underscores, and dollar signs (same rules as variables). Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, PHP, and XML.

Writing Your Own JavaScript Functions

How TO - Alerts Alerts. Alert messages can be used to notify the user about something special: danger, success, information or warning. The alert() method displays an alert box with a specified message and an OK button. An alert box is often used if you want to make sure information comes through to the user.

Note: The alert box takes the focus away from the current window, and forces the browser to read the message.

JavaScript - Functions

Do not overuse this method, as it prevents the user from. JS Functions Function Definitions JavaScript has three kind of popup boxes: Alert box, Confirm box, and Prompt box. Alert Box. An alert box is often used if you want to make sure information comes through to the user.

When an alert box pops up, the user will have to click "OK" to proceed. Syntax. The most common way to define a function in JavaScript is by using the function keyword, followed by a unique function name, a list of parameters (that might be empty), and a statement block surrounded by curly braces.

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How to write alert function in javascript
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