Window alert() Method in HTML

Взаимодействие: alert, prompt, confirm

Так как мы будем использовать браузер как демо-среду, нам нужно познакомиться с несколькими функциями его интерфейса, а именно: alert , prompt и confirm .

alert

С этой функцией мы уже знакомы. Она показывает сообщение и ждёт, пока пользователь нажмёт кнопку «ОК».

Это небольшое окно с сообщением называется модальным окном. Понятие модальное означает, что пользователь не может взаимодействовать с интерфейсом остальной части страницы, нажимать на другие кнопки и т.д. до тех пор, пока взаимодействует с окном. В данном случае – пока не будет нажата кнопка «OK».

prompt

Функция prompt принимает два аргумента:

result = prompt(title, [default]);

Этот код отобразит модальное окно с текстом, полем для ввода текста и кнопками OK/Отмена.

title Текст для отображения в окне. default Необязательный второй параметр, который устанавливает начальное значение в поле для текста в окне.

Квадратные скобки вокруг default в описанном выше синтаксисе означают, что параметр факультативный, необязательный.

Пользователь может напечатать что-либо в поле ввода и нажать OK. Введённый текст будет присвоен переменной result . Пользователь также может отменить ввод нажатием на кнопку «Отмена» или нажав на клавишу Esc . В этом случае значением result станет null .

Вызов prompt возвращает текст, указанный в поле для ввода, или null , если ввод отменён пользователем.

let age = prompt('Сколько тебе лет?', 100); alert(`Тебе $ лет!`); // Тебе 100 лет!

Второй параметр является необязательным, но если не указать его, то Internet Explorer вставит строку «undefined» в поле для ввода.

Запустите код в Internet Explorer и посмотрите на результат:

Чтобы prompt хорошо выглядел в IE, рекомендуется всегда указывать второй параметр:

confirm

Функция confirm отображает модальное окно с текстом вопроса question и двумя кнопками: OK и Отмена.

Результат – true , если нажата кнопка OK. В других случаях – false .

let isBoss = confirm("Ты здесь главный?"); alert( isBoss ); // true, если нажата OK

Итого

Мы рассмотрели 3 функции браузера для взаимодействия с пользователем:

alert показывает сообщение. prompt показывает сообщение и запрашивает ввод текста от пользователя. Возвращает напечатанный в поле ввода текст или null , если была нажата кнопка «Отмена» или Esc с клавиатуры. confirm показывает сообщение и ждёт, пока пользователь нажмёт OK или Отмена. Возвращает true , если нажата OK, и false , если нажата кнопка «Отмена» или Esc с клавиатуры.

Все эти методы являются модальными: останавливают выполнение скриптов и не позволяют пользователю взаимодействовать с остальной частью страницы до тех пор, пока окно не будет закрыто.

На все указанные методы распространяются два ограничения:

1. Расположение окон определяется браузером. Обычно окна находятся в центре.
2. Визуальное отображение окон зависит от браузера, и мы не можем изменить их вид.

Такова цена простоты. Есть другие способы показать более приятные глазу окна с богатой функциональностью для взаимодействия с пользователем, но если «навороты» не имеют значения, то данные методы работают отлично.

Источник

How to Create an Alert Box in HTML: A Complete Guide

Learn how to create custom alert boxes in HTML and JavaScript, including best practices and examples. Improve user experience with clear and concise messages.

• Using HTML Window alert() Method
• Creating Custom Alert Boxes
• How to create a custom alert box
• JavaScript Popup Boxes
• Streamlabs Desktop Alert Box
• Other helpful code examples for creating HTML alert boxes
• Conclusion
• How do you write an alert box in HTML?
• How do I add an alert box?
• What is the proper syntax for an alert box?
• How do I display in alert box?

Alert boxes are an essential part of web development, providing a convenient way to display important messages to users on websites. While HTML has a built-in alert() method, custom alert boxes can also be created using HTML, CSS, and JavaScript. This blog post will cover everything you need to know about creating alert boxes in HTML and JavaScript.

Using HTML Window alert() Method

The alert() method is a built-in method in HTML that is used to display a virtual alert box with a specified message and an OK button. This method is great for quick and simple alerts, but it cannot be customized. The alert box takes the focus away from the current window and forces the browser to read the message. While the alert() method is useful, it is important to follow best practices when using it.

Best Practices for Using the alert() Method

• Avoid overusing the alert() method. Using it too frequently can annoy users and lead to a poor user experience.
• Avoid using custom designs that might confuse users. The default design of the alert() method is familiar to most users and is easy to understand.

Creating Custom Alert Boxes

Custom alert boxes can be created using HTML, CSS, and JavaScript. This provides developers with greater control over the appearance and behavior of the alert box. Below are the steps to create a custom alert box :

Steps to Create a Custom Alert Box

Different Alert Boxes Using HTML, CSS, and JavaScript

Custom alert boxes can be designed using HTML, CSS, and JavaScript. Bootstrap is a popular CSS framework that has different alert styles for success, info, warning, and danger. SweetAlert JS is a JavaScript library that provides beautiful and customizable alert boxes. The possibilities for custom alert boxes are endless.

How to create a custom alert box

How to create a custom alert box — with HTML, CSS & JavaScript — Web Tutorial View Duration: 22:27

JavaScript Popup Boxes

JavaScript has three types of popup boxes: alert box, confirm box, and prompt box. Each box serves a different purpose and can be used to enhance the user experience on your website.

The Alert Box

The alert box is used to display a message to the user. It has an OK button that, when clicked, closes the box. The alert() method is used to create an alert box in JavaScript.

The Confirm Box

The confirm box is used to ask the user for confirmation. It has two buttons, OK and Cancel. The confirm() method is used to create a confirm box in JavaScript.

The Prompt Box

The prompt box is used to ask the user for input. It has an input field for the user to enter text and two buttons, OK and Cancel. The prompt() method is used to create a prompt box in JavaScript.

Cheatsheet for Different Popup Boxes in JavaScript

Here is a quick cheatsheet for the different popup boxes in JavaScript:

// Alert Box alert("Hello World!");// Confirm Box confirm("Are you sure?");// Prompt Box prompt("Please enter your name:", "John Doe"); 

Streamlabs Desktop Alert Box

Streamlabs Desktop is a popular streaming software that allows users to add an alert box to their streams. The alert box can be customized to display different types of alerts, such as new followers, donations, and subscribers. Here are the steps to add an alert box in Streamlabs Desktop:

1. Open Streamlabs Desktop and select Alert Box from the pop-up menu in Sources.
2. Customize the alert box using the available options in Streamlabs Desktop.
3. Save the changes and test the alert box.

Common Issues with Alert Boxes

Users may ignore the message if the alert box is too vague or if it appears too frequently. It is important to use alert boxes sparingly and to create clear and concise message s for users. Proper use of alert boxes can improve the user experience and prevent errors or confusion.

Other helpful code examples for creating HTML alert boxes

In html, html alert code example

 click me! function alert_me() 

In javascript, Javascript make alert box code example

In html, html alert code example

     h1 < color: green; >h2 < font-family: Impact; >body 
GeeksforGeeks
 
Window alert() Method
 
For displaying the alert message, double click the "Show Alert Message" button:
 Show Alert Message function myalert() 

Conclusion

Alert boxes are a simple and effective way to display important messages to users on websites. While the HTML alert() method is great for quick alerts, custom alert boxes can be created using HTML, CSS, and JavaScript. JavaScript has three types of popup boxes that can be used for more complex alerts. When using alert boxes, it’s important to follow best practices and create clear and concise messages for users. With this guide, you should now have a good understanding of how to create alert boxes in HTML and JavaScript.

Frequently Asked Questions — FAQs

What is the difference between the HTML alert() method and custom alert boxes?

The HTML alert() method is a quick way to display a message to users, but it cannot be customized. Custom alert boxes allow for more flexibility in design and functionality.

How can I create a custom alert box in HTML?

To create a custom alert box, HTML, CSS, and JavaScript can be used. Different alert boxes can be created using HTML, CSS, and JavaScript. Bootstrap has different alert styles for success, info, warning, and danger. SweetAlert JS can be used to create custom alert boxes in JavaScript.

What are the best practices for using alert boxes?

Best practices for using alert boxes include not overusing them and avoiding custom designs that might confuse users. It’s important to create clear and concise messages for users.

What are the different types of popup boxes in JavaScript?

JavaScript has three types of popup boxes: alert box, confirm box, and prompt box. The confirm box is used when a user needs to confirm or deny an action, while the prompt box is used for user input.

How can I improve the user experience with alert boxes?

To improve the user experience with alert boxes, it’s important to follow best practices and create clear and concise messages for users. It’s also important to avoid overusing alert boxes and to use custom designs sparingly.

How can I use Streamlabs Desktop Alert Box for my website?

To add an alert box in Streamlabs Desktop, select Alert Box from the pop-up menu in Sources. Common issues with alert boxes include users ignoring the message or the message being too vague. Proper use of alert boxes can improve the user experience and prevent errors or confusion.

Источник

Window: alert() method

window.alert() instructs the browser to display a dialog with an optional message, and to wait until the user dismisses the dialog.

Under some conditions — for example, when the user switches tabs — the browser may not actually display a dialog, or may not wait for the user to dismiss the dialog.

Syntax

Parameters

A string you want to display in the alert dialog, or, alternatively, an object that is converted into a string and displayed.

Return value

Examples

.alert("Hello world!"); alert("Hello world!"); 

Notes

The alert dialog should be used for messages which do not require any response on the part of the user, other than the acknowledgement of the message.

Dialog boxes are modal windows — they prevent the user from accessing the rest of the program’s interface until the dialog box is closed. For this reason, you should not overuse any function that creates a dialog box (or modal window).

Specifications

Browser compatibility

BCD tables only load in the browser

See also

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This page was last modified on Apr 8, 2023 by MDN contributors.

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Источник

How TO — Alerts

Alert messages can be used to notify the user about something special: danger, success, information or warning.

Create An Alert Message

Step 1) Add HTML:

Example

If you want the ability to close the alert message, add a element with an onclick attribute that says «when you click on me, hide my parent element» — which is the container (class=»alert»).

Tip: Use the HTML entity » × » to create the letter «x».

Step 2) Add CSS:

Style the alert box and the close button:

Example

/* The alert message box */
.alert padding: 20px;
background-color: #f44336; /* Red */
color: white;
margin-bottom: 15px;
>

/* The close button */
.closebtn margin-left: 15px;
color: white;
font-weight: bold;
float: right;
font-size: 22px;
line-height: 20px;
cursor: pointer;
transition: 0.3s;
>

/* When moving the mouse over the close button */
.closebtn:hover color: black;
>

Many Alerts

If you have many alert messages on a page, you can add the following script to close different alerts without using the onclick attribute on each element.

And, if you want the alerts to slowly fade out when you click on them, add opacity and transition to the alert class:

Example

// Get all elements with >var close = document.getElementsByClassName(«closebtn»);
var i;

// Loop through all close buttons
for (i = 0; i < close.length; i++) // When someone clicks on a close button
close[i].onclick = function()

// Get the parent of var div = this.parentElement;

// Set the opacity of div to 0 (transparent)
div.style.opacity = «0»;

// Hide the div after 600ms (the same amount of milliseconds it takes to fade out)
setTimeout(function()< div.style.display = "none"; >, 600);
>
>

Tip: Also check out Notes.

Источник