PHP method to get the first value of an array - PHP tutorial
reset (PHP 3, PHP 4, PHP 5)
reset -- Point the internal pointer of the array to the first element
Description
mixed reset (array &array)
reset() rewinds the internal pointer of array to the first cell and returns the value of the first array cell, or FALSE if the array is empty.
Example 1. reset() example
<?<span php
</span><span //</span><span 获取数组第一个值
//by www.jbxue.com</span>
<span $array</span> = <span array</span>('stepone', 'step two', 'step three', 'step four'<span );
</span><span //</span><span by default, the pointer is on the first element</span>
<span echo</span> <span current</span>(<span $array</span>) . "<br/>\n"; <span //</span><span "stepone"
// skip twosteps</span>
<span next</span>(<span $array</span><span );
</span><span next</span>(<span $array</span><span );
</span><span echo</span> <span current</span>(<span $array</span>) . "<br/>\n"; <span //</span><span "stepthree"
//reset pointer, start again on step one</span>
<span reset</span>(<span $array</span><span );
</span><span echo</span> <span current</span>(<span $array</span>) . "<br/>\n"; <span //</span><span "stepone"</span>
?>
next -- Move the internal pointer in the array forward one position
Description
mixed next (array &array)
Returns the value of the next cell pointed to by the internal pointer of the array, or returns FALSE when there are no more cells.
next() behaves similarly to current(), with one difference: the internal pointer is moved forward one position before returning the value. This means that it returns the value of the next array element and moves the array pointer forward one position. If moving the pointer results in moving the pointer beyond the end of the array element, next() returns FALSE.
Warning
If the array contains empty cells, or the value of the cell is 0, this function will also return FALSE when encountering these cells. To correctly iterate over an array that may contain empty cells or a cell value of 0, see the each() function.
Example 1. Usage examples of next() and related functions
<?<span php
</span><span //</span><span 数组迭代方法 next
//by www.jbxue.com</span>
<span $transport</span> = <span array</span>('foot', 'bike', 'car', 'plane'<span );
</span><span $mode</span> = <span current</span>(<span $transport</span>); <span //</span><span $mode = 'foot';</span>
<span $mode</span> = <span next</span>(<span $transport</span>); <span //</span><span $mode ='bike';</span>
<span $mode</span> = <span next</span>(<span $transport</span>); <span //</span><span $mode ='car';</span>
<span $mode</span> = <span prev</span>(<span $transport</span>); <span //</span><span $mode ='bike';</span>
<span $mode</span> = <span end</span>(<span $transport</span>); <span //</span><span $mode ='plane';</span>
?>
current -- Returns the current cell in the array
Description
mixed current (array &array)
Each array has an internal pointer pointing to its "current" cell, initially pointing to the first cell inserted into the array.
The current() function returns the value of the array unit currently pointed to by the internal pointer, without moving the pointer. If the internal pointer points beyond the end of the unit list, current() returns FALSE.
Warning
If the array contains an empty cell (0 or "", empty string), this function will also return FALSE when encountering this cell. This makes it impossible to use current() to determine whether the end of the array list has been reached. To correctly iterate over an array that may contain empty cells, use the each() function.
Example 1. Usage examples of current() and related functions
<?<span php
</span><span //</span><span 取当前数组元素</span>
<span $transport</span> = <span array</span>('foot', 'bike', 'car', 'plane'<span );
</span><span $mode</span> = <span current</span>(<span $transport</span>); <span //</span><span $mode = 'foot';</span>
<span $mode</span> = <span next</span>(<span $transport</span>); <span //</span><span $mode ='bike';</span>
<span $mode</span> = <span current</span>(<span $transport</span>); <span //</span><span $mode = 'bike';</span>
<span $mode</span> = <span prev</span>(<span $transport</span>); <span //</span><span $mode ='foot';</span>
<span $mode</span> = <span end</span>(<span $transport</span>); <span //</span><span $mode ='plane';</span>
<span $mode</span> = <span current</span>(<span $transport</span>); <span //</span><span $mode = 'plane';
//by www.jbxue.com 脚本学堂</span>
?>
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1668
14
1428
52
1329
25
1273
29
1256
24
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
