Plugin could not be activated because it triggered a fatal error, unexpected '['

Question

I'm attempting to dynamically create a text widget, add it to a named sidebar widget that my theme has already created ($sidebar_id = 'home-header-widget'), then populate the text widget with some preset content. I'm getting an error as indicated above at line 35 (commented below). Any ideas what I'm doing wrong?

Parse error: syntax error, unexpected '[' in C:....widgettest.php on line 35


<?php
/*
Plugin Name: Widget Test
*/


function cb_activate_widgettest(){

    $ops = get_option('widget_text');
    // find an $id that works...
    $ops[$id] = array(
      'title' => '',
      'text' => 'bar', // content?
    );
    update_option('widget_text', $ops);

    $sidebar_id = 'home-header-widget';
    $sidebars_widgets = get_option('sidebars_widgets');
    $sidebars_widgets[$sidebar_id] = ["widget_text-$id"];  //this is line 35
    update_option('sidebars_widgets', $sidebars_widgets);
}

register_activation_hook(__FILE__, 'cb_activate_widgettest');
?>

Answer 1

This part triggers it:

= ["widget_text-$id"]

Copy paste gone wrong or something? Square brackets used this way make no sense to PHP.