console
localStorage.setItem('show', null)
console.log(localStorage.show||'123')
console.log(typeof localStorage.show)
console.log(null||'123123')
console.log(undefined||'123123')
console.log(func())
function func(){
console.log(bar);
return bar();
function bar(){return 8}
}
var a=0;
function sth(){
var a=1;
return a;
}
console.log(a, sth());
<div class='box'></div>
.box{
width: 220px;
height: 220px;
padding: 20px;
border: 20px solid black;
margin: 20px;
background: red;
box-sizing: border-box;
}