箭头函数几个模版例子（便于自己查询）

// ES5
    var selected = allJobs.filter(function (job) {
      return job.isSelected();
    });
 // ES6
    var selected = allJobs.filter(job => job.isSelected());

// ES5
    var total = values.reduce(function (a, b) {
      return a + b;
    }, 0);
// ES6
    var total = values.reduce((a, b) => a + b, 0);

 // ES5
    $("#confetti-btn").click(function (event) {
      playTrumpet();
      fireConfettiCannon();
    });
 // ES6
    $("#confetti-btn").click(event => {
      playTrumpet();
      fireConfettiCannon();
    });