JSFiddle - React, Tailwind, and code Playground

by Zoxon

HTML

<div class="add-form">
	<label for="quantity">Добавить в корзину:</label>
	<div class="text">
	<input type="text" name="quantity" id="quantity" value="1" />
	    <a href="#" class="plusone">+</a>
	    <a href="#" class="minusone">-</a>
	</div>
	<a href="#" class="add-to-basket"></a>
	<div class="clear"></div>
</div>

JavaScript

$('.add-form .plusone').click(function() {
		var InpVal = parseInt($('.add-form input').val(), 10);
		if (!isNaN(InpVal)) {
			$('.add-form input').val(InpVal + 1);
		} else {
			$('.add-form input').val(1);
		}
		return false;
	});

	$('.add-form .minusone').click(function() {
		var InpVal = parseInt($('.add-form input').val(), 10);
		if (!isNaN(InpVal)) {
			if (InpVal > 1) {
				$('.add-form input').val(InpVal - 1);
			}
		} else {
			$('.add-form input').val(1);
		}
		return false;
	});