javascript cancel popup box

JavaScript is a front-end programming language commonly used for web design and interaction. In web pages, pop-up boxes are a very common way of interaction, which can prompt users to perform some operations or display some information. Sometimes, we may need to cancel the pop-up box. This article will introduce how to use JavaScript to cancel the pop-up box.

1. Using the confirmation box

In JavaScript, there is a built-in function confirm(), which can pop up a confirmation box to prompt the user to confirm or cancel an operation. The usage of this function is as follows:

confirm("确定要取消吗？");

This function will return a Boolean value true or false, indicating whether the user clicked Confirm or Cancel.

If we want to cancel the original pop-up box when the user clicks Cancel, we can use this function. Suppose our original pop-up box is written like this:

alert("这是一个弹框");

Now we want to cancel this pop-up box when the user clicks cancel. The code is as follows:

if(confirm("确定要取消吗？")) {
  alert("这是一个弹框");
}

The if statement is used here. The alert() function will be executed only when the return value of confirm() is true, otherwise it will not be executed.

2. Using timers

In JavaScript, you can use timers to cancel pop-up boxes. Suppose we have popped up a pop-up box:

var myAlert = alert("这是一个弹框");

We can use the setTimeout() function to set a timer, and then cancel the pop-up box in the callback function executed by the timer. The code is as follows:

var myAlert = alert("这是一个弹框");
var myTimer = setTimeout(function() {
  myAlert.close();
}, 5000);

In this example, we set a 5-second timer. When the timer fires, the callback function will be executed. The close() method is called in this callback function to close the pop-up box.

It should be noted that the way to close the pop-up box may vary from browser to browser. In some browsers, you can use the close() method, while in some browsers, you need to use the window.close() method. .

3. Using event listeners

In JavaScript, you can use event listeners to cancel pop-up boxes. Suppose we have already popped up a pop-up box:

var myAlert = alert("这是一个弹框");

We can add a click event listener to the current window, and then cancel the pop-up box in the callback function. The code is as follows:

var myAlert = alert("这是一个弹框");
window.addEventListener("click", function() {
  myAlert.close();
});

In this example, we add a click event listener to the window. When the user clicks anywhere, the callback function will be triggered. The close() method is called in this callback function to close the pop-up box.

It should be noted that when using event listeners, we need to confirm that the pop-up box has popped up and add a listener to the current window, otherwise logic errors may occur.

To sum up, JavaScript provides multiple ways to cancel the pop-up box, and developers can choose the appropriate method according to their needs. In addition, when canceling the pop-up box, you also need to pay attention to browser compatibility and logical correctness.

The above is the detailed content of javascript cancel popup box. For more information, please follow other related articles on the PHP Chinese website!