Home > Backend Development > PHP Tutorial > Three ways to implement chain operations in PHP

Three ways to implement chain operations in PHP

高洛峰
Release: 2023-03-05 16:04:01
Original
1216 people have browsed it

There are many string functions in php. For example, you need to filter the spaces at the end of the string first, and then find its length. The general way of writing is:

strlen(trim($str))
Copy after login
Copy after login

If you want to implement a chain operation similar to that in js , for example, how should I write like the following?

$str->trim()->strlen()
Copy after login
Copy after login

The following are three ways to achieve it:

Method 1. Use magic function __call combined with call_user_func to achieve

Thought: First define a string class StringHelper, the constructor directly assigns value, and then chain calls trim() and strlen() function, by using call_user_func in the called magic function __call() to handle the calling relationship, the implementation is as follows:

<?php


class StringHelper 
{
    private $value;
    
    function __construct($value)
    {
        $this->value = $value;
    }

    function __call($function, $args){
        $this->value = call_user_func($function, $this->value, $args[0]);
        return $this;
    }

    function strlen() {
        return strlen($this->value);
    }
}

$str = new StringHelper("  sd f  0");
echo $str->trim('0')->strlen();
Copy after login
Copy after login

Terminal execution script:

php test.php 
8
Copy after login
Copy after login

Method 2. Use magic function __call combined with call_user_func_array to achieve

<?php


class StringHelper 
{
    private $value;
    
    function __construct($value)
    {
        $this->value = $value;
    }

    function __call($function, $args){
        array_unshift($args, $this->value);
        $this->value = call_user_func_array($function, $args);
        return $this;
    }

    function strlen() {
        return strlen($this->value);
    }
}

$str = new StringHelper("  sd f  0");
echo $str->trim('0')->strlen();
Copy after login
Copy after login

Instructions:

array_unshift(array,value1,value2,value3...)
Copy after login
Copy after login

array_unshift() Function is used to insert new elements into the array. The values ​​of the new array will be inserted at the beginning of the array.

call_user_func() and call_user_func_array are both methods of dynamically calling functions. The difference lies in the way parameters are passed.

Method three, do not use magic function __call to achieve

Just modify _call() to trim() Just use a function:

public function trim($t)
{
    $this->value = trim($this->value, $t);
    return $this;
}
Copy after login
Copy after login

The point is to return the $this pointer to facilitate calling the latter function.


There are many string functions in php. For example, you need to filter the spaces at the end of the string first, and then find its length. The general way of writing is:

strlen(trim($str))
Copy after login
Copy after login

If you want to implement a chain operation similar to that in js, for example, how should you write it like the following?

$str->trim()->strlen()
Copy after login
Copy after login

The following are three ways to achieve it:

Method 1. Use magic function __call combined with call_user_func to achieve

Thought: First define a string class StringHelper, the constructor directly assigns value, and then chain calls trim() and strlen() function, by using call_user_func in the called magic function __call() to handle the calling relationship, the implementation is as follows:

<?php


class StringHelper 
{
    private $value;
    
    function __construct($value)
    {
        $this->value = $value;
    }

    function __call($function, $args){
        $this->value = call_user_func($function, $this->value, $args[0]);
        return $this;
    }

    function strlen() {
        return strlen($this->value);
    }
}

$str = new StringHelper("  sd f  0");
echo $str->trim('0')->strlen();
Copy after login
Copy after login

Terminal execution script:

php test.php 
8
Copy after login
Copy after login

Method 2. Use magic function __call combined with call_user_func_array to achieve

<?php


class StringHelper 
{
    private $value;
    
    function __construct($value)
    {
        $this->value = $value;
    }

    function __call($function, $args){
        array_unshift($args, $this->value);
        $this->value = call_user_func_array($function, $args);
        return $this;
    }

    function strlen() {
        return strlen($this->value);
    }
}

$str = new StringHelper("  sd f  0");
echo $str->trim('0')->strlen();
Copy after login
Copy after login

Instructions:

array_unshift(array,value1,value2,value3...)
Copy after login
Copy after login

array_unshift() Function is used to insert new elements into the array. The values ​​of the new array will be inserted at the beginning of the array.

call_user_func() and call_user_func_array are both methods of dynamically calling functions. The difference lies in the way parameters are passed.

Method three, do not use magic function __call to achieve

Just modify _call() to trim() Just use a function:

public function trim($t)
{
    $this->value = trim($this->value, $t);
    return $this;
}
Copy after login
Copy after login

The key point is to return the $this pointer to facilitate calling the latter function.

For more PHP three ways to implement chain operations, please pay attention to the PHP Chinese website for related articles!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template