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PHP 8.4.0 RC4 available for testing
Getting Started
Introduction
A simple tutorial
Language Reference
Basic syntax
Types
Variables
Constants
Expressions
Operators
Control Structures
Functions
Classes and Objects
Namespaces
Enumerations
Errors
Exceptions
Fibers
Generators
Attributes
References Explained
Predefined Variables
Predefined Exceptions
Predefined Interfaces and Classes
Predefined Attributes
Context options and parameters
Supported Protocols and Wrappers
Security
Introduction
General considerations
Installed as CGI binary
Installed as an Apache module
Session Security
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Database Security
Error Reporting
User Submitted Data
Hiding PHP
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HTTP authentication with PHP
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Command line usage
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DTrace Dynamic Tracing
Function Reference
Affecting PHP's Behaviour
Audio Formats Manipulation
Authentication Services
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Compression and Archive Extensions
Cryptography Extensions
Database Extensions
Date and Time Related Extensions
File System Related Extensions
Human Language and Character Encoding Support
Image Processing and Generation
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Non-Text MIME Output
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Variable and Type Related Extensions
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简介 »
« ReflectionException
PHP 手册
函数参考
变量与类型相关扩展
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变量处理
简介
安装/配置
运行时配置
变量处理函数
boolval
— 获取变量的布尔值
debug_zval_dump
— 将表示内部 zval 结构的字符串转储到输出
doubleval
— 别名 floatval
empty
— 检查变量是否为空
floatval
— 获取变量的浮点值
get_debug_type
— 以适合调试的方式获取变量的类型名称
get_defined_vars
— 返回由所有已定义变量所组成的数组
get_resource_id
— 返回给定资源的整数标识符
get_resource_type
— 返回资源类型
gettype
— 获取变量的类型
intval
— 获取变量的整数值
is_array
— 检测变量是否是数组
is_bool
— 检测变量是否是布尔值
is_callable
— 验证值是否可以在当前范围内作为函数调用。
is_countable
— 验证变量内容是否为可数值
is_double
— 别名 is_float
is_float
— 检测变量是否是浮点型
is_int
— 检测变量是否是整数
is_integer
— 别名 is_int
is_iterable
— 验证变量的内容是否为可迭代值
is_long
— 别名 is_int
is_null
— 检测变量是否是 null
is_numeric
— 检测变量是否是数字或数字字符串
is_object
— 检测变量是否是对象
is_real
— 别名 is_float
is_resource
— 查找变量是否为资源
is_scalar
— 查找变量是否是标量
is_string
— 检测变量的类型是否是字符串
isset
— 检测变量是否已声明并且其值不为 null
print_r
— 打印人类可读的变量信息
serialize
— 生成值的可存储表示
settype
— 设置变量的类型
strval
— 获取变量的字符串值
unserialize
— 从已存储的表示中创建 PHP 的值
unset
— 清除指定变量
var_dump
— 打印变量的相关信息
var_export
— 输出或返回变量的可解析字符串表示
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