面试题

有关面试题：

setTimeout(function(){ console.log(4); },0); console.log(3); new Promise(function(resolve){ console.log(1); resolve(); console.log(2); }).then(function(){ console.log(5); return 7; }).then(function(i){ console.log(i); }); console.log(6); 输出结果： 3 1 2 6 5 7 4 var arr = []; arr.prototype === undefined arr.__proto__ === Array.prototype Array.__proto__ === Function.prototype Array.prototype.__proto__ === Object.prototype var test = { name: 'myname', name2: this.name, getName : function(){ return this.name; }, getName2 : function(){ setTimeout(function(){ console.log(this.name); },1000) }, getName3 :function(){ setTimeout(()=>{ console.log(this.name); },1000) } } console.log(test.name2); console.log(test.getName); test.getName2(); test.getName3(); //myname

js实现数太大导致后面的数为零，两个字符串相加 参考学习：https://blog.csdn.net/Q1059081877Q/article/details/80689194