Functions in JavaScript run in the scope in which they are defined, not the scope in which they are executed.

• The scope attribute is determined when the function is defined, not when the function is called.

• Functions in JavaScript run in the scope in which they are defined, not the scope in which they are executed.

• eg.

  var name = "lw";
  
  function alert_1 () {
  
    alert(name);
  
  }
  
  function alert_2 () {
  
   var name = "zgm";
  
   alert_1();
  
  }
  
  alert_2();// 结果：lw