How do I print the elements of an object in Javascript?

This function is similar to the print_r php function: it runs over the elements of an object recursively and put…

November 17, 2009

This function is similar to the print_r php function: it runs over the elements of an object recursively and put them into a string. The output string will be shown in an alert box. This is very useful to debug javascript and to discover properties of undocumented objects.

* Function : dump()
* Arguments: The data - array,hash(associative array),object
*    The level - OPTIONAL
* Returns  : The textual representation of the array.
* This function was inspired by the print_r function of PHP.
* This will accept some data as the argument and return a
* text that will be a more readable version of the
* array/hash/object that is given.
function dump(arr,level) {
	var dumped_text = "";
	if(!level) level = 0;

	//The padding given at the beginning of the line.
	var level_padding = "";
	for(var j=0;j<level+1;j++) level_padding += "    ";

	if(typeof(arr) == 'object') { //Array/Hashes/Objects
		for(var item in arr) {
			var value = arr[item];
			if(typeof(value) == 'object') { //If it is an array,
				dumped_text += level_padding + "'" + item + "' ...\n";
				dumped_text += dump(value,level+1);
			} else {
				dumped_text += level_padding + "'" + item + "' => \"" + value + "\"\n";
	} else { //Stings/Chars/Numbers etc.
		dumped_text = "===>"+arr+"<===("+typeof(arr)+")";
	return dumped_text;

This function comes from Open Js site.


I'm a software engineer, an everyday web developer and a maker. I usually build sites with PHP, within or without WordPress. I build Internet of Things with Arduino and ESP8266. I'm the founder of and and I'm actually the Chief Technical Officer of Better Days web agency.


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