Working With Strings

<script>
  document.body.append(document.createElement('textarea'));
  document.body.append(document.createElement('button'));
  //const text = document.querySelector('textarea').value;
  document.querySelector('button').addEventListener('click',function(){
    const text = document.querySelector('textarea').value;
    //console.log(text);
    const rows = text.split('\n'); //先把一整段分成五段

    for (const [i, row] of rows.entries()){
      const [first, second] = row.toLowerCase().trim().split('_');
      const output = `${first}${second.replace(second[0], second[0].toUpperCase())}`
      console.log(`${output.padEnd(20)}${'%'.repeat(i + 1)}`);
    }
  });
</script>