在console.log中打印Javascript对象时的不同行为

Question

If we do a console.log() of an object, we see its attributes. However if the console.log includes other strings, we get only [object Object]

Question: Why does it not print out the object's attributes? How can we use console.log to print out both our string and the object's attributes? Underscore.js and node packages can be used if they help.

> myThing = {'name': 'Doge', 'value': 1000}
Object {name: "Doge", value: 1000}

> console.log(myThing)
Object {name: "Doge", value: 1000}

> console.log('Logging: ' + myThing)
Logging: [object Object]

Desired Output

Logging: Object {name: "Doge", value: 1000}

Answer 1

--In browser

because when you use console.log('Logging: ' + myThing) it uses string concatenation where the object myThing is converted to string representation [object Object]

You can use

console.log('Logging: ', myThing)

or use JSON.stringify() - in modern browsers(for old browsers use a library like json2 )

console.log('Logging: ' + JSON.stringify(myThing))

Answer 2

Node.js has a built-in module called, util and you can use util.inspect to display the Object.

var util = require("util");
myThing = {'name': 'Doge', 'value': 1000};
console.log(myThing);
console.log('Logging: ' + myThing);
console.log('Logging: ' + util.inspect(myThing));

Output

{ name: 'Doge', value: 1000 }
Logging: [object Object]
Logging: { name: 'Doge', value: 1000 }