php变量范围 [英] php variable scope

问题描述

我对php变量范围感到困惑. 例如:

i'm confused about the php variable scope. such as:

while(true){
    $var = "yes , it is a test!";
  }
  printf($var)

$var是在while语句范围内定义的，我们如何才能使其超出范围?我找不到文件的说明.

the $var is defined in while statement scope , how could we get it outside it's scope ? and i can't find explanation on the document .

我想知道php如何处理它的作用域.

i wonder how php deal with it's scope .

推荐答案

如果您执行while(true)，则不会过时，所以没关系.但是，如果您要表达一个真实的表情，就可以这样(这是一个无用的示例，我知道)

If you do while(true) you will not get out of the while, so it wouldn't matter. But if you would have a real expression, something like this (this is a useless example, i know)

$i=0
while($i<10){ 
   $var = "yes , it is a test!"; 
   $i++;
 } 
 printf($var);

将正常工作. 没有特殊的"while"变量作用域，printf将打印您的字符串.检查: http://php.net/manual/en/language.variables.scope .php

Will just work. There is no special "while" variable scope, the printf will print your string. check : http://php.net/manual/en/language.variables.scope.php

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