Js编程题汇总

var Foo = function(a) {  
  function bar() {   
    console.log(a); 
  };
  this.baz = function() {
      console.log(a);
  };
};

Foo.prototype = {  
  biz: function() {    
    console.log(a); 
  }
};

var f = new Foo(7); 
//预测输出结果：
f.bar(); // result: TypeError, f.bar is not a function.  
f.baz(); // result: 7  
f.biz(); // result: ReferenceError, a is not defined

{
  let a = 'secret';
  function f() {
    return a;
  }
}

{
  let a = 'secret';
  let f = function () {
    return a;
  };
}