ReflectionClass::getConstant

(PHP 5, PHP 7, PHP 8)

ReflectionClass::getConstant — 获取已定义的常量

说明

public ReflectionClass::getConstant(string $name): mixed

获取已定义的常量。

参数

name: 要获取的类常量的名称。

返回值

常量名称为 name 的值。如果在类中没有找到该常量，则返回 false 。

示例

示例 #1 使用 ReflectionClass::getConstant()

<?php

class Example {
    const C1 = false;
    const C2 = 'I am a constant';
}

$reflection = new ReflectionClass('Example');

var_dump($reflection->getConstant('C1'));
var_dump($reflection->getConstant('C2'));
var_dump($reflection->getConstant('C3'));
?>

以上示例会输出：

bool(false)
string(15) "I am a constant"
bool(false)

参见

ReflectionClass::getConstants() - 获取常量

改进此页面

了解如何改进此页面 • 提交拉取请求 • 报告一个错误

＋添加备注

用户贡献的备注 2 notes

down

aurelien dot tisserand at wavesoftware dot ch ¶

11 years ago

If the $name constant doesn't exist in the targetted class the function returns bool(false), not empty nor null but false (you to test with "==="

$constFounded = false ;
$this->currentlangClass = new ReflectionClass($langFile);
$this->currentlangClass->getConstant($constant);
if($myConst !== false){
              $constFounded = true ;
}

down

Bhimsen ¶

12 years ago

The "getconstant" method can be used to get the value associated with a constant 
of a particular class that you are examining.
The following code snippet shows this:

<?php
    class Test{
        const ONE = "Number one";
        const TWO = "Number two";
    }
    
    $obj = new ReflectionClass( "Test" );
    echo $obj->getconstant( "ONE" )."\n";
    echo $obj->getconstant( "TWO" )."\n";
    
?>

output:
Number one
Number two