Fixing the width and height of the post thumbnail

CMS & WordPress
1

I’m having trouble trying to set the width and height of my post thumbnail.

Here is the link for the image

1024×750 255 KB

As you can see both of the post have different dimensions

I have tried a couple of times in fixing the height and width of my post in fuction.php but no luck. Basically what i want to accomplish is that if i upload an image in the featured image regardless of size it would come out with a height of 250px and a width of 250 px. But whatever i do it seems incorrect.

This is the code that i have encoded

index.php

 <?php if ( has_post_thumbnail() ) { the_post_thumbnail(); } ?>

functions.php

//post thumbnail support 3

 add_theme_support( 'post-thumbnails', array( 'post' ) );
 set_post_thumbnail_size( 250, 250 );

Am i missing something? I’m still trying to code in wordpress and PHP language. Basically i’m still a newbie. I really want to accomplish this without having to really on plugins

2

You can set the width and height either in the HTML and/or in the CSS.

HTML:

<img src="" width="250" height="250" alt="">

CSS:

.post img {width: 250px; height: 250px;}