我使用以下代码来确定复选框是否已勾选，然后显示一些文本（如果有/没有）作为测试。

选中时，它工作正常，文本显示。

当它被取消选中时，我会在下面的代码中注释的两行中得到下面的消息。

非法字符串偏移量“chec\\u checkbox\\u field\\u 0”

<?php

function webdev_init() {
?>
    <h1>Title</h1>
    <h2>WedDev Overlay Plugin Options</h2>
    <form action=\'options.php\' method=\'post\'>
    <h2>Checking</h2>

    <?php
    settings_fields( \'my_option\' );
    do_settings_sections( \'checking\' );
    submit_button();
    ?>

    </form>
<?php
}

function chec_settings_init() {

    register_setting( \'my_option\', \'chec_settings\' );

    add_settings_section(
        \'chec_checking_section\',
        __( \'Your section description\', \'wp\' ),
        \'chec_settings_section_callback\',
        \'checking\'
    );

    add_settings_field(
        \'chec_checkbox_field_0\',
        __( \'Settings field description\', \'wp\' ),
        \'chec_checkbox_field_0_render\',
        \'checking\',
        \'chec_checking_section\'
    );
}

function chec_settings_section_callback() {

    echo __( \'This section description\', \'wp\' );

}

function chec_checkbox_field_0_render() {

    $options = get_option( \'chec_settings\' );
?>

//Error message on line bellow
<input type=\'checkbox\' name=\'chec_settings[chec_checkbox_field_0]\' value=\'1\' <?php if ( 1 == $options[\'chec_checkbox_field_0\'] ) echo \'checked="checked"\'; ?> />

<?php
}

$options = get_option( \'chec_settings\' );
//Error message on line bellow
if ( $options[\'chec_checkbox_field_0\'] == \'1\' ) {
    echo \'Checked\';
} else {
    echo \'Unchecked\';
}