以下是对php中三个等号(===)和两个等号(==)的区别进行了详细的分析介绍,需要的朋友可以过来参考下
先举个列子:
比如你一个函数会返回这几种情况:
1、大于0的数
2、小于0的数
3、等于0的数(也就是0啦)
4、False(失败时)
这时候如果你想捕获失败的情况,你就必须用===,而不能用==
因为==除了会匹配第4种情况外,还会匹配第3种情况,因为0也是假!
三个等号代表比较对象的类型也要一致。两个等号表示只要值相等就满足条件。
再来补充一些:
$a='2';//字符型2
$b=2;//数值型2
$a==$b,是对的,香港服务器,都是2
$a===$b,是不对的,美国服务器,因为$a是字符型$b是数值型,虚拟主机,值虽一样,但类型不一样。
还有就是“linvo1986 - 六级”说的那种“0”了。

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

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

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

SublimeText3 Chinese version
Chinese version, very easy to use

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
