JSFiddle - React, Tailwind, and code Playground

HTML

<input id='input1' placeholder='1' value='Hello'>
<input id='input2' placeholder='2' value='World'>
<input id='input3' placeholder='3'>
<input id='input4' placeholder='4'>
<input id='input5' placeholder='5'>
<input id='input6' placeholder='6'>
<input id='input7' placeholder='7'>
<input id='input8' placeholder='8'>

JavaScript

alert($('input[id^="input"][value=""]').length);