object Object
in Programming on Javascript
Javascript Basic
object Object is Object which have no inheritance.
How to use Object API
Object Reference
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object
What is the usage diffrence between two methods?
//Object.keys()
var arr = ["a", "b", "c"];
console.log('Object.keys(arr)', Object.keys(arr)); // return key values.
//Object.prototype.toString()
var o = new Object();
console.log('o.toString()', o.toString());
in case of second methods, only Object can use the method.
Object extension
Object.prototype.contain = function(neddle) {
for(var name in this){
if(this[name] === neddle){
return true;
}
}
return false;
}
var o = {'name':'euido', 'city':'seoul'}
console.log(o.contain('euido')); //true
var a = ['euido','leezche','grapittie'];
console.log(a.contain('leezche')); //true
be careful when you extend Object
Object.prototype.contain = function(neddle) {
for(var name in this){
if(this[name] === neddle){
return true;
}
}
return false;
}
var o = {'name':'euido', 'city':'seoul'}
var a = ['euido','leezche','grapittie'];
for(var name in o){
if(o.hasOwnPropery(name)){
console.log(name);
}
}
// the reason why we need to use hasOwnPropery function is
// if o has also contain methods so it shows for loop as well.