js参数传递

var num1 = 10;
var num2 = num1;
console.log(num2);//10

num2 += 1;
console.log(num1); //10
console.log(num2); //11

var obj1 = {
  name : "111"
};
var obj2 = obj1;
console.log(obj2.name); //111
obj2.name = "222";
console.log(obj1.name); //222

var count = 10;
function num(num1){
   num1 = 1;
   return num1;
}
var result = num(count);
console.log(result);//1

console.log(count);//10，并未变成1

 

var person  = {
    name : "Tom"
};
function obj(peo){
    peo.name = "Jerry";
    return peo;
}
var result = obj(person);
console.log(result.name);// Jerry
console.log(person.name);// Jerry

var person = {
    name : "Tom"
}; 
function obj(peo){
    peo = {
       name : "Jerry"
    };
    return peo;
}
var result = obj(person);
console.log(result.name);// Jerry

console.log(person.name);// Tom

参考：https://www.cnblogs.com/open-wang/p/5208606.html