Every PHP dev who has already debugged a script must have used the var_dump() function. This function lets you see what values a variable or array has with them. Unfortunately such a function does not exist in Javascript 
Here is an advanced one supporting:
- String
- Numbers
- Function (the code is displayed)
- Object
- Boolean
- Array
Example:
<script type="text/javascript">
function hello_world(){alert("Hello World!");}
foo = [];
foo["yes"] = 1;
foo["no"] = false;
foo["alert"] = alert;
foo["hello world"] = hello_world;
var_dump(foo);
function var_dump(obj, level) {
var dump = "(<i>" + (typeof obj) + "</i>) : ";
var level_nbsp = "";
if(typeof level == "undefined"){var level = 1;}
for(i = 0; i < 5*level; i++){level_nbsp += " ";}
switch(typeof obj){
case "string":
dump += obj + "<br/>\n";
break;
case "boolean":
dump += (obj?"true":"false") + "<br/>\n";
break;
case "number":
case "function":
dump += obj.toString() + "<br/>\n";
break;
default:
dump += "<br>\n";
for(var key in obj){dump += level_nbsp +"<b>" + key + "</b> " + var_dump(obj[key], level + 1);}
break;
}
if(level == 1){
var dump_area = document.createElement('dump_area');
dump_area.innerHTML = dump;
document.body.appendChild(dump_area);
}
else{return dump;}
}
</script>
The previous code will display:
(object) :
yes (number) : 1
no (boolean) : false
alert (function) : function alert() { [native code] }
hello world (function) : function hello_world(){alert("Hello World!");}
Hope this helps.
If you’re a PHP developer, this article about an upgraded version of the PHP
var_dump() function may interest you.
