Js之 toString() 和 String() 的区别

Eg1:
console.log([1,2,3,4].constructor.toString().indexOf("Array") > -1 );//
console.log(String([1,2, 3,4].constructor).indexOf("Array") > -1);
 
返回
True
True
 
==============
 
Eg2:
var test = null;
var test_1;
  // String()
console.log(String(test));
console.log(String(test_1));
 
  // toString()
console.log(test.toString());
console.log(test_1.toString());
 
返回
null
undefined
TypeError: Cannot read property 'toString' of null