Laziness is like a lock, which bolts you out of the storehouse of information and makes you an intellectual starveling. –Bernard Shaw
懒惰就象一把枷锁，锁住了知识的仓库，使你的
var n1=1;
n2=2;
function f1(){var n3=3;
n4=4;
}
console.log("n1="+n1);
console.log("n2="+n2);
//console.log("n3="+n3) Error: n3 is not defined
//console.log("n4="+n4) Error: n4 is not defi
