js json数据格式转换为formdata格式

var newObj = {
    "userPhone":tel,
    "userName":userName,
    "city":jDate.cityxzdq,
    "flyzAj": flyzAj,
    "sqclType":sqclType,
    "sqclFiles":sqclFiles,
    "saryList":saryList
}

var formDatas = new FormData();
makeFormData(newObj, formDatas); // 调用此方法

function makeFormData(obj, form_data){
    var data = [];
    if (obj instanceof File){
        data.push({key: "", value: obj});
    }else if (obj instanceof Array ){
        for (var j=0,len=obj.length;j<len;j++){
            var arr = makeFormData(obj[j]);
            for (var k=0,l=arr.length;k<l;k++){
                var key = !!form_data ? j+arr[k].key : "["+j+"]"+arr[k].key;
                data.push({key: key, value: arr[k].value})
            }
        }
    }else if (typeof obj == 'object'){
        for (var j in obj){
            var arr = makeFormData(obj[j]);
            for (var k=0,l=arr.length;k<l;k++){
                var key = !!form_data ? j+arr[k].key : "."+j+""+arr[k].key;
                data.push({key: key, value: arr[k].value})
            }
        }
    }else{
        data.push({key: "", value: obj});
    }
    if (!!form_data){
        // 封装
        for (var i=0,len=data.length;i<len;i++){
            form_data.append(data[i].key, data[i].value)
        }
    }else{
        return data;
    }
};