What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]

Question

I would like to see the structure of object in JavaScript (for debugging). Is there anything similar to var_dump in PHP?

Answer 1

Most modern browsers have a console in their developer tools, useful for this sort of debugging.

console.log(myvar); 

Then you will get a nicely mapped out interface of the object/whatever in the console.

Check out the console documentation for more details.

Answer 2

Most common way:

console.log(object); 

However I must mention JSON.stringify which is useful to dump variables in non-browser scripts:

console.log( JSON.stringify(object) ); 

The JSON.stringify function also supports built-in prettification as pointed out by Simon Zyx.

Example:

var obj = {x: 1, y: 2, z: 3};  console.log( JSON.stringify(obj, null, 2) ); // spacing level = 2 

The above snippet will print:

{   "x": 1,   "y": 2,   "z": 3 } 

On caniuse.com you can view the browsers that support natively the JSON.stringify function: http://caniuse.com/json

You can also use the Douglas Crockford library to add JSON.stringify support on old browsers: https://github.com/douglascrockford/JSON-js

Docs for JSON.stringify: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify

I hope this helps :-)