几道js面试题

var x=10;
function fun(){
    console.log(x)
}
function show(f){
    var x=20;
    (function(){
        console.log(x);
        f();
    })()
}
show(fun);
var x = 1;
var output = (function() {
    delete x;
    return x;
})(3);
console.log(x);
console.log(output);
console.log(x);
var s='var z=1;';
function z(s){
    eval(s);
}
console.log(z(s));
var z=1,y=z=typeof y;
console.log(y,z);