$('#myDiv').fadeOut().html('帅哥, 你好！').fadeIn();

myStr1.replace('k', 'R').toUpperCase().substr(0,4); 

var usresData = [
 {firstName: 'Zhang', lastName: 'San', email: '111@qq.com', id: 102},
 {firstName: 'Li', lastName: 'Si', email: '222@qq.com', id: 103},
 {firstName: 'Wang', lastName: 'Wu', email: '333@qq.com', id: 105}
];

function getCaseName(str) {
 return str.replace(/\w\S*/g, function(txt){
  return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
 })
}

var userController = {
 currentUser = '',
 findUser = function (userEmail) {
  var arrayLength = usersData.length, i;
  for (i = arrayLength - 1; i >= 0; i--) {
   if (usersData[i].email === userEmail) {
    this.currentUser = usersData[i];
    break;
   }
  }
  return this;
 },
 formatName: function () {
  if (this.currentUser) {
   this.currentUser.fullName = getCaseName(this.currentUser.firstName) + ' ' + getCaseName(this.currentUser.lastName);
  }
  return this;
 },
 createLayout: function () {
  if (this.currentUser) {
   this.currentUser.viewData = '<h2>成员: ' + this.currentUser.fullName + '</h2>'​
   + '<p>ID: ' + this.currentUser.id + '</p>' + '<p>Email: ' + this.currentUser.email + '</p>';
  }
  return this;
 },
 displayUser: function () {
  if (!this.currentUser) return;
  $('.members-wrapper').append(this.currentUser.viewData);
 }
}

userController.findUser('111@qq.com').formatName().createLayout().displayUser();