我可以在console.log中将对象打印为类似于日期的字符串吗？

Question

When I create the new Date object and using console.log shows not object but time as string. However, MyObject is print as Object.

Example:

const date = new Date();
console.log(date);

const MyObject = function() {
  this.name = 'Stackoverflow',
  this.desc = 'is Good'
};
console.log(new MyObject());

Result:

2017-04-06T06:28:03.393Z
MyObject { name: 'Stackoverflow', desc: 'is Good' }

But I want to print MyObject like below format without using function or method.

Stackoverflow is Good

In java, I can override toString () to implement this. Is it possible in javascript too?

Answer 1

I don't think console.log provides any mechanism to tell it what representation to use for the object.

You can do console.log(String(new MyObject())); and give MyObject.prototype a toString method:

const MyObject = function() {
  this.name = 'Stackoverflow';
  this.desc = 'is Good';
};
MyObject.prototype.toString = function() {
    return this.name + this.desc;
};

As you're using ES2015+ features (I see that from const ), you might also consider class syntax:

class MyObject {
  constructor() {
    this.name = 'Stackoverflow';
    this.desc = 'is Good';
  }
  toString() {
    return this.name + this.desc;
  }
}

Answer 2

tips: in javascript ,you still can use "override" a method to impletement it

demo:

let myobj={id:1,name:'hello'};

Object.prototype.toString=function(){ 

   return this.id+' and '+this.name

}; //override toString of 'Global' Object.

console.log(obj.toString());// print: 1 is hello