function foo() {
var a = 2;
function bar() {
console.log( a );
}
return bar;
}
var baz = foo();
baz(); // 2 -- 哇噢,看到闭包了,伙计。
<div id="position">水平垂直居中的对象</div>
#position {
background-color:red;
position:absolute;
top: 50%;
left: 50%;
width:200px;
height: 40px;
margin: -20px 0 0 -100px;
/* padding: 0 20px; */
line-height:240%;
text-align:center;
}
@media screen and (max-width:599px) {
nav li {
display: inline;
}
}
@media screen and (max-width:100px){
#position {
background-color:blue;
}
}
body{
background-color:green;
}