Countable::count

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

Countable::count — 统计一个对象的元素个数

说明

abstract public Countable::count(): int

当使用 count()函数作用于一个实现了 Countable的对象时这个方法会被执行.

参数

此函数没有参数。

返回值

The custom count as an integer.

注意:
The return value is cast to an integer.

范例

示例 #1 Countable::count() example


<?php
class myCounter implements Countable {
    public function count() {
        static $count = 0;
        return ++$count;
    }
}

$counter = new myCounter;

for($i=0; $i<10; ++$i) {
    echo "I have been count()ed " . count($counter) . " times\n";
}
?>

以上例程的输出类似于：

I have been count()ed 1 times
I have been count()ed 2 times
I have been count()ed 3 times
I have been count()ed 4 times
I have been count()ed 5 times
I have been count()ed 6 times
I have been count()ed 7 times
I have been count()ed 8 times
I have been count()ed 9 times
I have been count()ed 10 times

add a note

User Contributed Notes 1 note

down

SenseException ¶

8 years ago


Even though Countable::count method is called when the object implementing Countable is used in count() function, the second parameter of count, $mode, has no influence to your class method. 

$mode is not passed to  Countable::count:

<?php

class Foo implements Countable
{
    public function count()
    {
        var_dump(func_get_args());
        return 1;
    }
}

count(new Foo(), COUNT_RECURSIVE);

?>

var_dump output:

array(0) {
}

add a note

官方地址：https://www.php.net/manual/en/countable.count.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 PHP 8.1 adodb手册 opcache预加载 Composer的Packagist资源 mysql面试题支持php7的性能采集扩展 php扩展开发 PHP7 mcrypt替代方案 Packagist / Composer 中国全量镜像如何在Composer中为GitLab实例设置访问令牌 PHP mkdir()写出来的权限与mode值不符合 PHP-FPM进程数的设定

略微加速

PHP官方手册 - 互联网笔记

Countable::count

说明

参数

返回值

范例

User Contributed Notes 1 note