dash.height===undefined
"age" in dash
最骚的操作就是一个元素的值是undefined
let dash={
name:"悟空",
age:500,
u:undefined
};
alert(dash.u);
dash.height===undefined
"age" in dash
最骚的操作就是一个元素的值是undefined
let dash={
name:"悟空",
age:500,
u:undefined
};
alert(dash.u);