


The functions of the is_a() function and instanceof operator in PHP are similar, so what are the differences between them? The following article will give you a brief understanding of the is_a() function and instanceof, and introduce the difference between the is_a() function and instanceof. I hope it will be helpful to you. [Video tutorial recommendation: PHP tutorial]
##PHP is_a() function
is_a() function is a built-in function in PHP that checks whether a given object belongs to a given class; it also checks whether the given class is one of the parent classes of the given object.Basic syntax:
is_a( $object, $class_name, $allow_string )
Parameters: is_a() function can accept the following three parameters
●Object: Use to save the test object. ●Class_name: used to save the class name. ● Allow_string: If the set value is False, string class names are not allowed to be used as objects.Return value: If the object belongs to the given class, or this class is one of its parent classes, the is_a() function returns True, otherwise it returns a False value.
Let’s learn about the is_a() function through code examples.<?php class hello { var $store = 'Hello PHP!'; } $PHP= new hello(); // 检查$PHP是否是hello类的对象 if (is_a($PHP, 'hello')) { echo "Yes"; } ?>Output:
Yes
PHP instanceof operator
Use instanceof operator in PHP to find out whether an object Is an instantiated instance of a class.Basic syntax:
$a instanceof MyClass
Operands: The instanceof operator contains the following two operands
● $a: represents the object. ● MyClass: Indicates a class name. Return value: If the object belongs to the given class, or this class is one of its parent classes, it returns True, otherwise it returns a False value. Let’s learn about the instanceof operator through code examples.<?php class hello { var $store = 'Hello PHP!'; } $PHP= new hello(); // 检查$PHP是否是hello类的对象 if ($PHP instanceof hello) { echo "Yes"; } ?>Output:
Yes
The difference between is_a() function and instanceof operator
● is_a() is a function, and instanceof is a language structure. The is_a() function will be significantly slower since it has all the overhead of performing a function call. ●In the case of function callbacks (such as array_map), because instanceof is not a function, it is a language construct, so it cannot be used as a callback. However, callbacks can be used in the is_a() function. ●The usage time of the direct class name in InstanceOf is shorter than that of the is_a() function. Example://语法短(比较) $a instanceof MyClass is_a( $a, MyClass::class )●is_a() is a function that takes an object as parameter 1 and a string as parameter 2, while instanceof takes an object as parameter 1 and can Pass a class name, object instance, or class identifier (class name without quotes) as argument 2.
Example of is_a():
//只有这样才能调用它 is_a($object,$string);
instanceof example:
//对象实例 $object instanceof $otherObject; //字符串类名 $object instanceof $string; //类的标识符 $object instanceof ClassName;The above is the entire content of this article, I hope it will be helpful to everyone's study. For more exciting content, you can pay attention to the relevant tutorial columns of the PHP Chinese website! ! !
The above is the detailed content of What is the difference between is_a() function and instanceof in PHP?. For more information, please follow other related articles on the PHP Chinese website!

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。


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

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

Dreamweaver Mac version
Visual web development tools

Notepad++7.3.1
Easy-to-use and free code editor

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
