How to check if anonymous object has a method?
typeof myObj.prop2 === 'function';
will let you know if the function is defined.
if(typeof myObj.prop2 === 'function') {
alert("It's a function");
} else if (typeof myObj.prop2 === 'undefined') {
alert("It's undefined");
} else {
alert("It's neither undefined nor a function. It's a " + typeof myObj.prop2);
}
You want hasOwnProperty()
:
var myObj1 = {
prop1: 'no',
prop2: function () { return false; }
}
var myObj2 = {
prop1: 'no'
}
console.log(myObj1.hasOwnProperty('prop2')); // returns true
console.log(myObj2.hasOwnProperty('prop2')); // returns false
References: Mozilla, Microsoft, phrogz.net.