如何在验证脚本中排除必填字段？ [复制]

Question

我正在尝试创建一个基于必填字段进行验证的多步骤表单。 我正在使用的当前 Javascript 只是查找填写的字段以验证表单。但是如何让它忽略 html 中未标记为“必填”的字段？

谢谢！

function validateForm() {
  // This function deals with validation of the form fields
  var x, y, i, valid = true;
  x = document.getElementsByClassName("tab");
  y = x[currentTab].getElementsByTagName("input");
  // A loop that checks every input field in the current tab:
  for (i = 0; i < y.length; i++) {
    // If a field is empty...
    if (y[i].value == "") {
      // add an "invalid" class to the field:
      y[i].className += " invalid";
      // and set the current valid status to false:
      valid = false;
    }
  }
  // If the valid status is true, mark the step as finished and valid:
  if (valid) {
    document.getElementsByClassName("step")[currentTab].className += " finish";
  }
  return valid; // return the valid status
}

Answer 1

但是如何让它忽略 html 中未标记为“必填”的字段？

以下解决方案检查input 元素中的required 属性。所以在for循环中，你要做的第一件事是if(!y[i].required){ continue; }，换句话说，如果y[i].required是undefined，那么continue（或者跳过这个迭代）。

function validateForm() {
  // This function deals with validation of the form fields
  var x, y, i, valid = true;
  x = document.getElementsByClassName("tab");
  y = x[currentTab].getElementsByTagName("input");
  // A loop that checks every input field in the current tab:
  for (i = 0; i < y.length; i++) {
    // --> if y[i].required is undefined... skip to the next <--
    if(!y[i].required){ continue; }
    // If a field is empty...
    if (y[i].value == "") {
      // add an "invalid" class to the field:
      y[i].className += " invalid";
      // and set the current valid status to false:
      valid = false;
    }
  }
  // If the valid status is true, mark the step as finished and valid:
  if (valid) {
    document.getElementsByClassName("step")[currentTab].className += " finish";
  }
  return valid; // return the valid status
}