Pure Javascript to limit(hide) characters and show on clikc

scripts.js

window.addEventListener('load', function() {
	const testimonialItems = document.querySelectorAll('.testimonial-item');
	testimonialItems.forEach(testimonialItem => {
		var maxLength = 200;
		const textLength = testimonialItem.innerText.length;
		if(textLength > maxLength) {
			var shortContent = testimonialItem.innerText.substring(0, maxLength); /*split the content in two parts*/
			var longContent = testimonialItem.innerText.substring(maxLength);
			testimonialItem.innerHTML = shortContent + '<i class="read_more">...<strong> Read More</strong></i>';
			const readbtn = testimonialItem.querySelectorAll('.read_more');
			readbtn.forEach(showMore =>{
				showMore.addEventListener('click', function(event){
					showMore.style.display = "none"; /*hide Read More link*/
					testimonialItem.innerHTML = shortContent + longContent; /*show all content*/
				});
			});
		}
	});
});

This function limits the number of characters to 200. Hides the remaining and add "...read more" which is clickable. Upon click reveals the entire texts.
Implementation example: https://codepen.io/utk_adk/pen/PoQQggm