how to set alt & title for featured image get_the_post_thumbnail

Question

I want to set post title for alt and title Attribute in this code

what should I do?

<?php
if ( true == get_theme_mod( 'archive_featured_images', true ) ) :
    if ( has_post_thumbnail() && ( get_the_post_thumbnail() != '' ) ) :
        echo '<a class="featured-image" href="'. esc_url( get_permalink() ) .'" title="'. the_title_attribute( 'echo=0' ) .'">';
        echo '<span itemprop="image" itemscope itemtype="https://schema.org/ImageObject">';
        the_post_thumbnail( 'mudra-featured-image' );
        $mudra_image = wp_get_attachment_image_src( get_post_thumbnail_id(), 'mudra-featured-image' );
        echo '<meta itemprop="url" content="' . esc_url( $mudra_image[0] ) . '">';
        echo '<meta itemprop="width" content="' . esc_attr( $mudra_image[1] ) . '">';
        echo '<meta itemprop="height" content="' . esc_attr( $mudra_image[2] ) . '">';
        echo '</span>';
        echo '</a>';
    endif;
endif;
?>

Answer 1

You can use the second parameter of the_post_thumbnail() function.

the_post_thumbnail( 'mudra-featured-image', ['alt' => get_the_title()] );

Another option, you can do this using the filter wp_get_attachment_image_attributes

add_filter('wp_get_attachment_image_attributes', function($attr){
    $attr['alt'] = get_the_title();
    return $attr;
});

Note, using the filter will affect other images printed using any function that depends on wp_get_attachment_image()

So, you may use the other two attributes passed to the callback function for more control. Example, if you want apply this only on the size "mudra-featured-image", your code will be something like this

add_filter( 'wp_get_attachment_image_attributes', function( $attr, $attachment, $size ){

    // Return the current $attr array as it is if the size is not "mudra-featured-image"
    if( 'mudra-featured-image' !== $size ){
        return $attr;
    }
    // If it is our targeted size then, change the "alt" attribute
    $attr['alt'] = get_the_title();
    return $attr;

}, 10, 3 );

Answer 2

You can use the third parameter of the function:

get_the_post_thumbnail($post, $size, $attr);

Example:

get_the_post_thumbnail(
    $post,
    '',
    array(
       'alt' => 'anything',
       'title' => 'anything',
    )
);

Parameters

$post

(int|WP_Post) (Optional) Post ID or WP_Post object. Default is global $post. Default value: null

$size

(string|int[]) (Optional) Image size. Accepts any registered image size name, or an array of width and height values in pixels (in that order). Default value: 'post-thumbnail'

$attr (string|array) (Optional) Query string or array of attributes. Default value: ''

You can get more details here: https://developer.wordpress.org/reference/functions/get_the_post_thumbnail/