Question

为什么即使我的代码是这样的：

if ( ! function_exists('get_values')){
    global $str;
    function getValues($getThem, $tpar, $vpiso, $tcomi, $tgas, $ttotal){
            $totalPares = $tpar;
            $ventasPiso = $vpiso;
            $totalComisiones = $tcomi;
            $totalGastos = $tgas;
            $totalTotal = $ttotal;
            $str = $totalPares . "," . $ventasPiso . "," . $totalComisiones . "," . $totalGastos . "," . $totalTotal;
            return $str;
    }

    function getEm(){
        return $str;
    }
}

我无法覆盖$ str的值。它总是打印 - 如果我试图回显它，并且在“getEm”函数内它表示它是一个未定义的变量。

这是codeigniter框架中的帮助文件。

修改

仍然给我这个错误：

遇到PHP错误

严重性：注意

消息：未定义的变量：str

文件名：   助手/ helper_common_functions_helper.php

行号：15

Answer 1

global $str;

您需要研究变量范围。函数有自己的作用域，除非你在开始时global $variable访问该函数之外的变量。还请注意，使用全局变量是“nono”，应该不惜一切代价避免使用。

function getValues($getThem, $tpar, $vpiso, $tcomi, $tgas, $ttotal){
        global $str;
        $totalPares = $tpar;
        $ventasPiso = $vpiso;
        $totalComisiones = $tcomi;
        $totalGastos = $tgas;
        $totalTotal = $ttotal;
        $str = $totalPares . "," . $ventasPiso . "," . $totalComisiones . "," . $totalGastos . "," . $totalTotal;
        return $str;
}

Answer 2

如果您想要在某个范围内保持状态，您应该从中创建一个类。不推荐global

class MyClass {
  private $str = "a";

  public function getValues($getThem, $tpar, $vpiso, $tcomi, $tgas, $ttotal){
        $totalPares = $tpar;
        $ventasPiso = $vpiso;
        $totalComisiones = $tcomi;
        $totalGastos = $tgas;
        $totalTotal = $ttotal;
        $str = $totalPares . "," . $ventasPiso . "," . $totalComisiones . "," . $totalGastos . "," . $totalTotal;
        return $str;
  }

  public function getEm(){
    return $this->str;
  }
}

然后你需要在使用它之前实例化（当然），但你要保持你的范围清洁

$x = new MyClass;
echo $x->getEm();

如果仅使用静态属性和方法创建类，则不需要对其进行实例化（MyClass:getEm()）。

Answer 3

全局变量看起来错位，也许这有帮助：

if ( ! function_exists('get_values')){
    function getValues($getThem, $tpar, $vpiso, $tcomi, $tgas, $ttotal){
        global $str; ##### <- place it here
            $totalPares = $tpar;
            $ventasPiso = $vpiso;
            $totalComisiones = $tcomi;
            $totalGastos = $tgas;
            $totalTotal = $ttotal;
            $str = $totalPares . "," . $ventasPiso . "," . $totalComisiones . "," . $totalGastos . "," . $totalTotal;
            return $str;
    }

    function getEm(){
        global $str; ##### <- place it here
        return $str;
    }
}

旁注：我真的不知道codeigniter的设计有多好，但使用名为$str的全局变量听起来像是在惹麻烦。给它一个更好地反映它属于什么以及它代表什么的名称。 $getValues_Helper_String虽然字符串不多说。 Some tips on finding a name

无法理解一种行为

3 个答案: