如何使用 HTML 模式属性允许两个输入值

Question

I'm looking to constrain user input using an HTML pattern attribute on a text input, I didn't want to use a select or radio buttons tag for design purposes. I tried many approaches but none of them allowed me to get to what I want.

 <form action="" method="post"> <input type="text" class="study" name="study" placeholder="Enter your year of study L1-3,M1-2 " pattern="[LlMm]+[1-2-3]" maxlength="2" title="only L1,L2,L3 and M1,M2 are allowed" required> <button name="submit" class="btn" type="submit">Register</button> </form>

Answer 1

found the answer [L]{1}[1-3]|[M]{1}[1-2] using https://regex101.com and using logical or enter image description here

Answer 2

Use this pattern: [LM]{1}[0-9]{1}

You can check if this work for you with this tool: https://regex101.com