Need help changing image in javascript if src contains PHP

I have an image I want to change on click using javascript. The only problem is that the src is a theme mod which is obviously PHP. When I click on the image, the javascript works as expected, but the less than(<), greater than(>) and a few other symbols are changed. Code Below.

HTML:

<div id='slide-holder'>
     <img id='sliderjoint' src="<?php echo esc_url(get_theme_mod('selectimage2'));?>"
</div>

Javascript:

function slide(){
		var pic = document.getElementById('sliderjoint');
		pic.src = "<?php echo esc_url(get_theme_mod('selectimage2'));?>"
		console.log(pic.src);
	}

	var el = document.getElementById('slide-holder');
	el.addEventListener('click', slide);

Should I be using AJAX? I don’t really see how that would help me but I just need someone to point me in the right direction.