> For the complete documentation index, see [llms.txt](https://edge.gitbook.io/edge/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://edge.gitbook.io/edge/skill/overload.md).

# 函数重载

```javascript
// addMethod - By John Resig (MIT Licensed)
function addMethod(object, name, fn) {
  var old = object[name]

  object[name] = function() {
    if (fn.length === arguments.length) return fn.apply(this, arguments)
    else if (typeof old === 'function') return old.apply(this, arguments)
  }
}

function Users() {
  addMethod(Users.prototype, 'find', function() {
    console.log('Find all users...')
  })
  addMethod(Users.prototype, 'find', function(name) {
    console.log('Find a user by name')
  })
  addMethod(Users.prototype, 'find', function(first, last) {
    console.log('Find a user by first and last name')
  })
}

var users = new Users()
users.find() // Finds all
users.find('John') // Finds users by name
users.find('John', 'Resig') // Finds users by first and last name
users.find('John', 'E', 'Resig') // Does nothing
```