关于defineProperty

Question

function Archiver() {  var temperature = null;  var archive = [];  Object.defineProperty(this, 'temperature', {    get: function() {      console.log('get!');      return temperature;    },    set: function(value) {      temperature = value;      archive.push({ val: temperature });    }  });  this.getArchive = function() { return archive; };}var arc = new Archiver();arc.temperature; // 'get!'arc.temperature = 11;arc.temperature = 13;arc.getArchive(); // [{ val: 11 }, { val: 13 }]有大神解释下这4个输出是怎么来的吗？请输入代码