How to jump to the upper page in php

How to jump to the upper-level page in PHP: 1. By setting the "Location" parameter of the "header()" function, the page jump operation can be realized; 2. By embedding "JavaScript" code in PHP , you can perform the jump operation after the page is loaded; 3. The page jump can be achieved through the "go()" method of the "history" object, where the parameter is the number of levels of the page to be jumped.

The operating environment of this article: Windows 10 system, php8.1.3 version, dell g3 computer.

In the process of developing web applications, we often encounter the need to jump to the upper-level page. In PHP, different technologies and methods can be used to achieve page jumps. This article will introduce several commonly used methods to help developers better understand and apply them.

1. Use the header() function to jump to the page

PHP’s header() function can send original HTTP header information, including jump instructions. By setting the Location parameter of the header() function, the page jump operation can be implemented.

The specific code is as follows:

<?php
header("Location: " . $_SERVER[&#39;HTTP_REFERER&#39;]);
exit;
?>

In the above code, we use $_SERVER['HTTP_REFERER'] to obtain the upper-level page URL of the current page, and use the header() function to The URL is set to the Location parameter, and then the exit() function is called to terminate the execution of the script.

It should be noted that the header() function needs to be called before other output, otherwise an error will be reported. At the same time, in order to ensure a successful jump, make sure that no HTML content or other HTTP headers are output before the header() function is called. It is recommended to place the header() function call at the top of the PHP file.

2. Use JavaScript to jump

In addition to the header() function that comes with PHP, you can also use JavaScript to jump to the page. By embedding JavaScript code in PHP, you can perform a jump operation after the page is loaded.

The specific code is as follows:

<?php
echo &#39;<script>window.location.href="&#39; . $_SERVER[&#39;HTTP_REFERER&#39;] . &#39;";</script>&#39;;
exit;
?>

In the above code, we use the window.location.href property of JavaScript to specify the target URL to jump to. Output JavaScript code to the page by embedding echo statements in PHP.

It should also be noted that in order to ensure that the jump can be executed normally, make sure that no HTML content is output before the JavaScript code is output.

3. Use JavaScript’s history object to jump

Another way to use JavaScript to jump is to use the history object. Page jump can be achieved through the go() method of the history object, where the parameter is the level number of the page to be jumped.

The specific code is as follows:

<?php
echo &#39;<script>history.go(-1);</script>&#39;;
exit;
?>

In the above code, we called the history.go() method and passed in -1 as a parameter, which means returning to the previous page .

It should be noted that if the current page is the first page, that is, there is no superior page, using history.go(-1) will be invalid. In this case, you can use the isset() function in combination to determine whether the current page has a superior page.

Summary

This article introduces three common methods to implement the jump operation of PHP pages, namely using the header() function, using JavaScript to jump, And use JavaScript's history object to jump. Developers can choose the appropriate method to implement page jumps based on specific needs and actual conditions. No matter which method is used, you need to pay attention to calling the jump code at the appropriate time and ensure that no other HTTP headers or HTML content are output before the jump code to ensure a smooth jump.

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