如何使用保存属性名称的变量检查对象属性是否存在？

var myProp = 'prop';if(myObj.hasOwnProperty(myProp)){    alert("yes, i have that property");}

要么

var myProp = 'prop';if(myProp in myObj){    alert("yes, i have that property");}

要么

if('prop' in myObj){    alert("yes, i have that property");}

请注意，

hasOwnProperty

in

'constructor' inmyObj

myObj.hasOwnProperty('constructor')