


require is used as <font face="NSimsun">require("MyRequireFile.php");</font>
. This function is usually placed at the front of the PHP program. Before the PHP program is executed, it will first read in the file specified by require and make it a part of the PHP program web page. Commonly used functions can also be introduced into web pages in this way.
include is used as <font face="NSimsun">include("MyIncludeFile.php");</font>
. This function is generally placed in the processing part of flow control. The PHP program webpage only reads the include file when it reads it. In this way, the process of program execution can be simplified.
The two of them have exactly the same purpose, and it doesn’t necessarily have to be which one is in the front and which one is in the middle. The most fundamental difference between them is the way they handle errors.
If there is an error in require a file, then the program will interrupt execution and display a fatal error
If there is an error in include a file, then the program will not end, but will continue to execute and display a Warning error.
The following are supplements:
1. include has a return value, but require does not.
2. include() includes and runs the specified file. When the processing fails, include() generates a warning. The imported program code will be executed, and these programs will have and call the source file when executed. to the same variable scope as the include() statement. You can import static pages from the same server.
3. The function of include_once() is almost the same as include()
The only difference is that include_once() will first check whether the file to be imported has been imported elsewhere in the program. If it has been passed, it will not be imported again (this function is sometimes very important. For example, if the file to be imported declares some functions that you have defined yourself, then if you import this file repeatedly in the same program , an error message will occur when importing for the second time, because PHP does not allow functions with the same name to be declared twice).
4. require() will read the contents of the target file and replace itself with the read contents. If the processing fails, require() will cause a fatal error.
This reading and substitution action occurs when the PHP engine compiles your program code, not when the PHP engine starts executing the compiled program code (the way the PHP 3.0 engine works is to compile a line Execute one line, but this has changed since PHP 4.0. PHP 4.0 first compiles the entire program code, and then executes the compiled program code at once. No program code will be executed during the compilation process. ). require() is usually used to import static content, while include() is suitable for importing dynamic program code.
5. Like include_once(), require_once() will first check whether the content of the target file has been imported before. If so, the same content will not be imported again.
5. require is an unconditional inclusion, that is, if require is added to a process, require will be executed first regardless of whether the condition is true or not.
7. require is usually placed at the front of the PHP program. Before the PHP program is executed, it will first read in the file specified by require and make it a part of the PHP program web page. Commonly used functions can also be introduced into web pages in this way.
8. Include is generally placed in the processing part of the process control. The PHP program webpage only reads the included file when it reads it. This method can simplify the process of program execution.
The difference between require(), include(), require_once() and include_once()

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。

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。

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。

在PHP中,可以利用implode()函数的第一个参数来设置没有分隔符,该函数的第一个参数用于规定数组元素之间放置的内容,默认是空字符串,也可将第一个参数设置为空,语法为“implode(数组)”或者“implode("",数组)”。

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。


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