帮客之家(www.Bkjia.com)教程 在使用 PHP 程序的过程中,我们经常会碰到页面出现空白,页面出现空白是因为程序运行过程中遇到问题不能正常执行,而 PHP 环境配置信息又阻止向页面输出 PHP 返回的错误信息,遇到这样的问题不要惊慌,只要打开PHP的报错信息,然后根据错误信息提示就能找到问题的原因,然后逐步解决。
下面介绍如何在程序中设置PHP的报错级别:
我们在程序运行的开始利用 error_reporting()函数设置 PHP 的报错级别并返回当前级别。
以下为引用的内容: error_reporting(report_level); |
以下为引用的内容: 如果参数 level 未指定,当前报错级别将被返回。下面几项是 level 可能的值:值 常量 描述1 E_ERROR Fatal run-time errors. Errors that can not be recovered from. Execution of the script is halted2 E_WARNING Non-fatal run-time errors. Execution of the script is not halted4 E_PARSE Compile-time parse errors. Parse errors should only be generated by the parser8 E_NOTICE Run-time notices. The script found something that might be an error, but could also happen when running a script normally16 E_CORE_ERROR Fatal errors at PHP startup. This is like an E_ERROR in the PHP core32 E_CORE_WARNING Non-fatal errors at PHP startup. This is like an E_WARNING in the PHP core64 E_COMPILE_ERROR Fatal compile-time errors. This is like an E_ERROR generated by the Zend Scripting Engine128 E_COMPILE_WARNING Non-fatal compile-time errors. This is like an E_WARNING generated by the Zend Scripting Engine256 E_USER_ERROR Fatal user-generated error. This is like an E_ERROR set by the programmer using the PHP function trigger_error()512 E_USER_WARNING Non-fatal user-generated warning. This is like an E_WARNING set by the programmer using the PHP function trigger_error()1024 E_USER_NOTICE User-generated notice. This is like an E_NOTICE set by the programmer using the PHP function trigger_error()2048 E_STRICT Run-time notices. PHP suggest changes to your code to help interoperability and compatibility of the code4096 E_RECOVERABLE_ERROR Catchable fatal error. This is like an E_ERROR but can be caught by a user defined handle (see also set_error_handler())8191 E_ALL All errors and warnings, except level E_STRICT (E_STRICT will be part of E_ALL as of PHP 6.0) |
例子:
以下为引用的内容: 任意数目的以上选项都可以用“或”来连接(用 OR 或 |),这样可以报告所有需要的各级别错误。例如,下面的代码关闭了用户自定义的错误和警告,执行了某些操作,然后恢复到原始的报错级别://禁用错误报告error_reporting(0);//报告运行时错误error_reporting(E_ERROR | E_WARNING | E_PARSE);//报告所有错误error_reporting(E_ALL);?> |

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。

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。

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。


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