<!DOCTYPE html>
<html lang="zh"> <head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<title>javascript 闭包 面试题</title>
</head> <body>
<script>
function fn(n, o) {
console.log(o);
return {
fn: function(m) {
return fn(m, n);
}
};
}
var a = fn(0); //undefined
a.fn(1); //0
a.fn(2); //0
a.fn(3); //0
console.log('------------');
var b = fn(0).fn(1).fn(2).fn(3); //undefined,0,1,2
console.log('------------');
var c = fn(0).fn(1); //undefined,0
c.fn(2); //1
c.fn(3); //1
</script>
</body> </html>