JS多个表单数据提交下的serialize()应用实例分析

function serialize(form){
      var parts = [],
        field = null,
        i,
        len,
        j,
        optLen,
        option,
        optValue;
      for (i=0, len=form.elements.length; i < len; i++){
        field = form.elements[i];
        switch(field.type){
          case "select-one":
          case "select-multiple":
            if (field.name.length){
              for (j=0, optLen = field.options.length; j < optLen; j++){
                option = field.options[j];
                if (option.selected){
                  optValue = "";
                  if (option.hasAttribute){
                    optValue = (option.hasAttribute("value") ? option.value : option.text);
                  } else {
                    optValue = (option.attributes["value"].specified ? option.value : option.text);
                  }
                  parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(optValue));
                }
              }
            }
            break;
          case undefined:   //fieldset
          case "file":    //file input
          case "submit":   //submit button
          case "reset":    //reset button
          case "button":   //custom button
            break;
          case "radio":    //radio button
          case "checkbox":  //checkbox
            if (!field.checked){
              break;
            }
            /* falls through */
          default:
            //don't include form fields without names
            if (field.name.length){
              parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(field.value));
            }
        }
      }
      console.log(parts);
      return parts.join("&");
}

function serialize(form){
      var parts = {},
        field = null,
        i,
        len,
        j,
        optLen,
        option,
        optValue;
      for (i=0, len=form.elements.length; i < len; i++){
        field = form.elements[i];
        switch(field.type){
          case "select-one":
          case "select-multiple":
            if (field.name.length){
              for (j=0, optLen = field.options.length; j < optLen; j++){
                option = field.options[j];
                if (option.selected){
                  optValue = "";
                  if (option.hasAttribute){
                    optValue = (option.hasAttribute("value") ? option.value : option.text);
                  } else {
                    optValue = (option.attributes["value"].specified ? option.value : option.text);
                  }
                  //将数据改为对象形式
                  Object.defineProperty(parts, encodeURIComponent(field.name), {
                    value:encodeURIComponent(optValue),
                    enumerable:true //为真表示可枚举，只有可枚举才能出现在JSON.stringify()转换的json数据中
                  });
                }
              }
            }
            break;
          case undefined:   //fieldset
          case "file":    //file input
          case "submit":   //submit button
          case "reset":    //reset button
          case "button":   //custom button
            break;
          case "radio":    //radio button
          case "checkbox":  //checkbox
            if (!field.checked){
              break;
            }
            /* falls through */
          default:
            //don't include form fields without names
            if (field.name.length){
              //构建对象
              Object.defineProperty(parts, encodeURIComponent(field.name), {
                    value:encodeURIComponent(field.value),
                    enumerable:true  //为真表示可枚举，只有可枚举才能出现在JSON.stringify()转换的json数据中
                  });
            }
        }
      }
      console.log(parts);
      return parts;
}