常用js函数封装
判断object 判断undefined 判断非undefined 转换成字符串 数组转换成对象 判断object function isObject(obj){ return obj !== null && typeof obj==='object' } 判断undefined function isUndef(v){ return v===undefined || v===null } 判断非undefined function isUndef(v){ return v!==undefined && v!==null } 转换成字符串 function toString(val){ return val == null? '': typeof val==='object'? JSON.stringify(val): String(val); } 数组转换成对象 function toObject(arr){ var res={}; arr.forEach((item,index)=>{ res[index]=item; }); return res } 来源: https://www.cnblogs.com/jingouli/p/11811201.html