一、点(.)或方框号([ ])
var obj = {
test: '123'
}
obj.test
obj['test']
二、in 运算符
var obj = {
test: '123'
}
test in obj
三、hasOwnProperty()
var obj = {
test: '123'
}
obj.hasOwnProperty('test')
var obj = {
test: '123'
}
obj.test
obj['test']
var obj = {
test: '123'
}
test in obj
var obj = {
test: '123'
}
obj.hasOwnProperty('test')