如何在CodeIgniter的视图中使用这个看似简单的循环？

In the view, right before the footer, I want to load three JavaScript files. So, the controller sets three variables. For example, $js_1 = "bootstrap.js", $js_2 = '' and $js_3 = "tinymce.js", which may or may not be empty. The logic is, it should echo only if the variable is not empty. I also want to use the ternary if operator.

This was the best I could try.

for ($i = 1; $i <= 3; $i++)
{
    echo (!empty ('$js_' . $i)) ? get_jscript('$js_' . $i) : NULL;
}

The function get_jscript() simply returns the HTML script src.

function get_jscript($js) 
{
    return '<script type="text/javascript" src="' . $js . '"></script> ';
}

Please note that I intend to ask this question to primarily learn the correct PHP syntax and not just load JS in the view.

This has some great info on how to use variable variables.

for ($i = 1; $i <= 3; $i++)
{
    echo (!empty (${'js_'.$i})) ? get_jscript(${'js_'.$i}) : NULL;
}

if you can create a array like this->

$javascript = array('js_1' => "bootstrap.js", 'js_2' => '', 'js_3' = "tinymce.js");

then in your view you have to just call a method

loop_javascript($javascript);

it's better to create a function in codeigniter helper and call that helper in controller's function (check how to use helpers in codeingiter) https://ellislab.com/codeigniter/user-guide/general/helpers.html->

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

if ( ! function_exists('loop_javascript'))
{
    function loop_javascript($jscript_array)
    {
        foreach($jscript_array as $key =>$value){
            if($value != ''){
                echo '<script type="text/javascript" src="' . $value. '"></script>';
            }
        }
    }   
}

for ($i = 1; $i <= 3; $i++)
{
    if(!empty($js.'_'.$i)){ echo get_jscript($js.'_'.$i); echo "</br>";}
}

function get_jscript($js) 
{
    return '<script type="text/javascript" src="' . $js . '"></script> ';
}