How to check WP Customize Control

Question

I’m not sure what exactly you’re trying to accomplish, but if you’re wanting to manipulate customizer controls until the customize_register action has fired. So do something like this:

add_action( 'customize_register', function( $wp_customize ) {
    $control = $wp_customize->get_control( 'header_text' );
    if ( $control ) {
        error_log( 'header_text control exists' );
    } else {
        error_log( 'header_text control does not exist' );
    }
}, 100 );