How to add custom logo in WordPress theme code example

Example 1: sile logo wordpress programmatically

$custom_logo_id = get_theme_mod( 'custom_logo' );
$logo = wp_get_attachment_image_src( $custom_logo_id , 'full' );
if ( has_custom_logo() ) {
        echo '<img src="' . esc_url( $logo[0] ) . '" alt="' . get_bloginfo( 'name' ) . '">';
} else {
        echo '<h1>'. get_bloginfo( 'name' ) .'</h1>';
}

Example 2: adding logo support to wordpress site

add_theme_support( 'custom-logo' );

Example 3: adding logo support to wordpress site

if ( function_exists( 'the_custom_logo' ) ) {
 the_custom_logo();
}

Example 4: how to add site logo in wordpress

function themename_custom_logo_setup() {
 $defaults = array(
 'height'      => 100,
 'width'       => 400,
 'flex-height' => true,
 'flex-width'  => true,
 'header-text' => array( 'site-title', 'site-description' ),
 );
 add_theme_support( 'custom-logo', $defaults );
}
add_action( 'after_setup_theme', 'themename_custom_logo_setup' );