在PHP中：如何调用之前在另一个函数内定义的函数内的$变量？ [英] In PHP: How to call a $variable inside one function that was defined previously inside another function?

问题描述

我刚刚开始使用面向对象的PHP，并且遇到以下问题：

我有一个包含一个包含特定脚本的函数的类。我需要在同一个类的另一个函数中调用位于该脚本中的变量。

例如：

  class helloWorld {
 
 function sayHello（）{
 echoHello; 
 $ var =World; 
} 
 
函数sayWorld（）{
 echo $ var; 
} 
 
 
} 
  

在上述例如，我想调用$ var，它是在前一个函数中定义的变量。这不起作用，所以我怎么做到这一点？

解决方案

您应该在类中创建var，而不是函数，因为当函数结束变量将被取消设置（由于函数终止）...

  class helloWorld {
 
 private $ var; 
 
函数sayHello（）{
 echoHello; 
 $ this-> var =World; 
} 
 
函数sayWorld（）{
 echo $ this-> var; 
} 
 
 
} 
？> 
  

如果您将变量声明为 public ，它可以被所有其他类直接访问，而如果你声明变量为 private ，它只能在同一个类中访问。

 <？php 
 Class First {
 private $ a; 
 public $ b; 
 
 public function create（）{
 $ this-> a = 1; //没问题
 $ thia-> b = 2; //没问题
} 
 
公共函数geta（）{
 return $ this-> a; 
} 
 private function getb（）{
 return $ this-> b; 
 
 
 
第二类{
 
函数test（）{
 $ a = new第一个; //创建一个First Class的对象$ a。 
 $ a-> create（）; //调用公共函数create .. 
 echo $ a-> b; //在类中确定var是公共的，并且可以在任何地方访问
 echo $ a-> a; //在hte类中的问题var是私有的
 echo $ a-> geta（）; //确定类中的A值是通过公共函数获得的，类中的值$ a不能正确访问
 echo $ a-> getb（）; //错误的getb函数是私人的，它只能从类里面访问
} 
} 
？> 
  

I'm just starting with Object Oriented PHP and I have the following issue:

I have a class that contains a function that contains a certain script. I need to call a variable located in that script within another function further down the same class.

For example:

class helloWorld {

function sayHello() {
     echo "Hello";
     $var = "World";
}

function sayWorld() {
     echo $var;
}


}

in the above example I want to call $var which is a variable that was defined inside a previous function. This doesn't work though, so how can I do this?

解决方案

you should create the var in the class, not in the function, because when the function end the variable will be unset (due to function termination)...

class helloWorld {

private $var;

function sayHello() {
     echo "Hello";
     $this->var = "World";
}

function sayWorld() {
     echo $this->var;
}


}
?>

If you declare the Variable as public, it's accessible directly by all the others classes, whereas if you declare the variable as private, it's accessible only in the same class..

<?php
 Class First {
  private $a;
  public $b;

  public function create(){
    $this->a=1; //no problem
    $thia->b=2; //no problem
  }

  public function geta(){
    return $this->a;
  }
  private function getb(){
    return $this->b;
  }
 }

 Class Second{

  function test(){
    $a=new First; //create object $a that is a First Class.
    $a->create(); // call the public function create..
    echo $a->b; //ok in the class the var is public and it's accessible by everywhere
    echo $a->a; //problem in hte class the var is private
    echo $a->geta(); //ok the A value from class is get through the public function, the value $a in the class is not dicrectly accessible
    echo $a->getb(); //error the getb function is private and it's accessible only from inside the class
  }
}
?>

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