07c08-3.php

介绍PHP5的给类型函数应用

<?php
// Define a class that will store values for any property it is given,
//  and format them nicely
class Data_Formatter {
    // The data storage array
    private $data = array();

    // Method to set any variable passed to this object.
    public function __set($name, $value) {
        if (is_int($value)) {
            // It is an integer, format it with commas, but no decimal
            $new_value = number_format($value, 0);
        } elseif (is_float($value)) {
            // It is a float value, format it with commas, and 2 decimals:
            $new_value = number_format($value, 2);
        } elseif (is_bool($value)) {
            // A boolean value, turn it into the string 'true' or 'false'
            $new_value = $value ? 'true' : 'false';
        } else {
            // Otherwise just store the data as is:
            $new_value = $value;
        }
        
        // Now store the data in our array
        $this->data[$name] = $new_value;
    }
    
    // A method to return any values that are set:
    public function __get($name) {
        if (isset($this->data[$name])) { return $this->data[$name]; }
    }

    // A method that will allow 'isset' to work on these variables
    public function __isset($name) {
        return isset($this->data[$name]);
    }
    
    // Finally a method to allow 'unset' calls to work on these variables
    public function __unset($name) {
        unset($this->data[$name]);
    }
}

// Create a data holding object & store some data in it:
$data = new Data_Formatter();
$data->number = 1200;
$data->money = 189000.452;
$data->lies = false;
$data->place = 'Mount Airy';

// Now echo these values out to see their formatted values:
//   1,200     189,000.45     false     Mount Airy
echo "<p>The value of 'number' is {$data->number}</p>";
echo "<p>The value of 'money' is {$data->money}</p>";
echo "<p>The value of 'lies' is {$data->lies}</p>";
echo "<p>The value of 'place' is {$data->place}</p>";
?>