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Is it possible to override JavaScript's toString() function to provide meaningful output for debugging? Ask Question

tag-icon • tag-icon javascript debugging tostring
Is it possible to override JavaScript's toString() function to provide meaningful output for debugging? Ask Question

When I console.log() an object in my JavaScript program, I just see the output [object Object], which is not very helpful in figuring out what object (or even what type of object) it is.

In C# I'm used to overriding ToString() to be able to customize the debugger representation of an object. Is there anything similar I can do in JavaScript?

ベストアンサー1

You can override toString in Javascript as well. See example:

function Foo() {}

// toString override added to prototype of Foo class
Foo.prototype.toString = function() {
  return "[object Foo]";
}

var f = new Foo();
console.log("" + f); // console displays [object Foo]

See this discussion on how to determine object type name in JavaScript.

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