


First look at a special case:
var_dump(0 == 'false'), returns bool(true), PHP determines that 0 is equal to any string;
var_dump(0==='false'), returns bool( false), the types and values must be equal if they are congruent.
var_dump(0 == false), returns bool(true),
The reasons for the above results (translated from php official documentation):
1. For bool type:
When you output the bool type or When used in a statement, it will be converted into a number , true becomes 1, and false becomes 0.
For example, $a = true; var_dump($a+1), returns (int)2; $a is converted to 1, and the sum is 2;
A bool variable expresses a true value, and Rather than expressing a 0 or 1; Boolean types are not iconic constants, they have values.
2. String type:
php will always automatically try to convert strings into numbers. For example, var_dump('abc'+3'), returns int(3),
First 'abc' is converted into the number 0, and the addition becomes 3;
Method to detect the type of variable:
1. var_dump ($param) , will return the type and value of the variable.
2. Use is_int(), is_bool(), is_string(); functions to return true and false,
commonly used type conversion methods.
Variable $param
Integer type (int)$param
Character type (string)$param
Boolean type (bool)$param
Another way to convert to Boolean type: $a = !5, $a is false ,$a = !!5,$a is true;
The above introduces the reasons why 0 == false, 0 == false will be equal, and false ! = false in php. , including relevant content, I hope it will be helpful to friends who are interested in PHP tutorials.

dump文件通常是指一种二进制文件,也被称为转储文件或核心转储文件。这种文件是计算机系统在遇到严重错误或异常情况时生成的,用于存储系统或应用程序的状态、堆栈、寄存器、内存映像、日志等信息。

在计算机中,dump的中文意思为“转储”,一般指将数据导出、转存成文件或静态形式,即将动态(易失)的数据,保存为静态的数据(持久数据)。像程序这种本来就保存在存储介质(如硬盘)中的数据,是没有必要dump。

PHP函数中true的含义详解在PHP中,true是一个布尔值,代表"真"或者"是"的状态。在函数中使用true通常用于表达一个条件成立或者返回一个成功的状态。本文将从不同的角度详细解释在PHP函数中true的含义,以及给出具体的代码示例说明。一、返回true的情况条件判断:在PHP函数中,true通常用于条件判断中,表示条件成立。例如:functioni

标题:PHP函数中true代表什么意思?在PHP编程中,true代表布尔值中的真,通常表示“真”的状态。在函数中使用true时,通常用于判断条件是否为真或执行某些操作。下面将通过具体的代码示例来说明在PHP函数中true代表什么意思。例子:

在Java开发中有有一个看似简单,但是在网上有大量关于话题和问题,就是equals()和==操作符有什么区别==:操作符用于比较两个对象的地址是否相等equals():方法用于比较两个对象的内容是否相等今日内容介绍,大约花费9分钟图片为了更好地理解这个区别,让我们看一个例子:Stringstr1=newString("Hello");Stringstr2=newString("Hello");System.out.println(str1.equals(str2));//输出trueSystem

项目最近添加了一个ip黑白名单的功能,发现如果ip过滤的拦截器返回false后前端会显示跨域,尝试修改MVC配置类后发现还是不行,最后在拦截器加了个判断就可以了@OverridepublicbooleanpreHandle(HttpServletRequestrequest,HttpServletResponseresponse,Objecthandler)throwsIOException{//-----------加上这个就好了-----------if(!(handlerinstanceo

linux param指的是“module_param”函数,其作用是传递命令行参数;在用户态下编程可以通过“main()”的参数来传递命令行参数,而编写一个内核模块则通过“module_param()”来传递参数。

redis-dump工具用于集群中的数据迁移搭建环境:192.168.19.201redis-cluster637970017002rvmredis-dump192.168.19.202redis-cluster637970017002192.168.19.203redis-cluster637970017002由于安装redis-dump工具需要使用rvm和gem工具所以要提前安装1.提前安装好安装rvm等工具所需要的依赖包#yum-yinstallzlibzlib-develpcrepcre


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