如何在不声明JS中的全局变量的情况下将值从一个函数传递给另一个函数？

Question

我只想将new1和new new2函数的值传递给new3函数

function new1(){
  var a = 5;
}

function new2(){
  var c=6;
}

function new3(){
  if(a<c){
    dosomething();
  }
}

Answer 1

(function(){

  var a, c; // Not global, but available to all three functions

  function new1(){
    a = 5;
  }

  function new2(){
    c = 6;
  }

  function new3(){
    if(a < c)
      doSomething();        
  }

  new1();
  new2();
  new3();

})();

function doSomething(){
  console.log("Doing something");
}

console.log(typeof a); // "undefined"

演示