Javascript 表单验证多次使用占位符

Question

我有一个表单验证将检查每个输入是否有效，但问题是当只有一个输入有效时所有输入都被视为有效。我已经转移返回真实位置，但它没有改变任何东西。

如有任何帮助，我们将不胜感激。

<form action="me.php" method="post" id="myform" onsubmit="return(val());">
  <input type="text" name="name" placeholder="Nama Anda *" class="i-form na"/>
  <input type="text" name="email" placeholder="Alamat E-mail *" class="i-from em"/>
  <input type="text" name="subject" placeholder="Judul Pesan *" class="i-form su"/>
  <textarea class="i-form isi" placeholder="Isi Pesan *"></textarea>
  <input type="submit" value="Send" class="btn"></input>

     function val(){
    var nama = $('.na').val();
    var email = $('.em').val();
    var subject = $('.su').val();
    var isi = $('.isi').val();
    if(nama === ''){
      $('.na').attr('placeholder','Masukkan Nama Anda');
      if(email === ''){
        $('.em').attr('placeholder','Masukkan E-mail Anda');
        if(subject === ''){
          $('.su').attr('placeholder','Masukkan subject Pesan');
            if(isi === ''){
              $('.isi').attr('placeholder','Masukkan Isi Pesan');
              return false;                  
            }
        }
      }
    } else {
      return true;
    }
    }

Answer 1

按照您说的检查所有输入即可。

function val(){
    var nama = $('.na').val();
    var email = $('.em').val();
    var subject = $('.su').val();
    var isi = $('.isi').val();
    var flag = true;
    if(nama === ''){
        $('.na').attr('placeholder','Masukkan Nama Anda');
        flag = false;
    }
    if(email === ''){
        $('.em').attr('placeholder','Masukkan E-mail Anda');
        flag = false;
    }
    if(subject === ''){
        $('.su').attr('placeholder','Masukkan subject Pesan');
        flag = false;
    }
    if(isi === ''){
        $('.isi').attr('placeholder','Masukkan Isi Pesan');
        flag = false;                  
    }
    return flag;
}