我对WordPress Customizer复选框的默认值有问题。

无论我在默认值中输入了什么，但该复选框始终在主题定制器中选中。

$wp_customize->add_setting( \'swastika_social_youtube\', array(
    \'capability\' => \'edit_theme_options\',
    \'default\'    =>  \'false\',
    \'sanitize_callback\' => \'swastika_sanitize_checkbox\',
    ) 
);

$wp_customize->add_control( \'swastika_social_youtube\', array(
    \'type\' => \'checkbox\',
    \'section\' => \'social_settings_section\', 
    \'label\'      => __( \'Show Youtube Icon\', \'swastika\' ),
    ) 
);

<?php if ( true == get_theme_mod( \'swastika_social_youtube\', false ) ) { ?> 
        <a href="#"><i class="fa fa-youtube-play" aria-hidden="true"></i></a>
    <?php } ?>