Three ways to implement chain operations in PHP

This article mainly introduces the three methods of PHP to implement chain operations, and analyzes the relevant implementation skills and usage precautions of PHP chain operations in the form of examples. Friends in need can refer to the following

for details As follows:

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 out its length. The general way of writing is:

strlen(trim($str))

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()

The following are three ways to achieve it:

Method 1. Use magic function_ _call is combined with call_user_func to implement

Idea: First define a string class StringHelper, the constructor directly assigns value, and then calls the trim() and strlen() functions in a chain, through Use 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(&#39;0&#39;)->strlen();

Terminal execution script:

php test.php 
8

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(&#39;0&#39;)->strlen();

Description:

##array_unshift(array,value1,value2,value3...)

array_unshift() Function is used to insert new elements into an 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 the magic function __call to achieve

Just need to modify

_call() to trim()Function is enough:

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

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

Related recommendations:

Query PHP string containing specified data

Characters in PHP Three ways of expressing strings

Commonly used string functions in php

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