如何为每个勾选的复选框创建一个递增 1 的变量

Question

我正在尝试创建一个函数，当勾选复选框时，该函数 returns 一个布尔值（1 或 0）....这里没有问题。我还希望它包含一个会话变量，每个选中的复选框都会递增 1。当我在提交表单 $_SESSION ['counter'] 后回显 $_SESSION ['counter'] 的值时，它仍然为零或我最初设置的任何值。谁能看到我哪里出错了？非常感谢您的提前帮助！

<?php
if(!isset($_SESSION)) 
{ 
    session_start(); 
} 


$_SESSION['counter']= 0; 


function checkbox_boolean ($checkboxID){ 

   $checkboxID= 0;
   if(isset($_POST[$checkboxID])){
       $checkboxID = 1;
       $_SESSION['counter']++;
   }
} 


if(isset($_POST['submit'])){

    echo $_SESSION['counter'];


    checkbox_boolean ('slot1');
    checkbox_boolean ('slot2');
    checkbox_boolean ('slot3');
    checkbox_boolean ('slot4');
    checkbox_boolean ('slot5');
    checkbox_boolean ('slot6');
    checkbox_boolean ('slot7');
    checkbox_boolean ('slot8');
}

?>

Answer 1

您正在设置

$_SESSION['counter']= 0;

每次调用 PHP 脚本时

归零。不管之前是什么，这条线总是将它重置为零。

将其更改为仅在它尚不存在时对其进行初始化。有点像..

if (!isset($_SESSION['counter'])) {
  $_SESSION['counter']= 0; 
}

Answer 2

您的代码中有不少错误，请参阅建议的修改

?php
    // dont need to test anything just call session_start()
    session_start();   

   // initialise only if not already in existance
    if ( !isset( $_SESSION['counter'] ) ) {
        $_SESSION['counter'] = 0; 
    }


function checkbox_boolean ($checkboxID){ 
   // this just destroyed whatever was passed in the $checkboxID parameter
   // $checkboxID= 0;  
   if(isset($_POST[$checkboxID])){
       // This does nothing useful
       //$checkboxID = 1;
       $_SESSION['counter']++;
   }
} 


if(isset($_POST['submit'])){

    echo 'Session counter before = ' . $_SESSION['counter'];

    checkbox_boolean ('slot1');
    checkbox_boolean ('slot2');
    checkbox_boolean ('slot3');
    checkbox_boolean ('slot4');
    checkbox_boolean ('slot5');
    checkbox_boolean ('slot6');
    checkbox_boolean ('slot7');
    checkbox_boolean ('slot8');

    echo 'Session counter after = ' . $_SESSION['counter'];
}

?>

如何为每个勾选的复选框创建一个递增 1 的变量

How to create a variable which increments by 1 for each checkbox which is ticked

php

function

increment