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How do I check if an object has a specific property in JavaScript?
...ty] !== undefined;
};
x = {'key': 1};
if (x.hasOwnProperty('key')) {
alert('have key!');
}
if (!x.hasOwnProperty('bar')) {
alert('no bar!');
}
A safer, but slower solution, as pointed out by Konrad Rudolph and Armin Ronacher would be:
Object.prototype.hasOwnProperty = function(property...
TypeScript function overloading
...myMethod(a: number, b: string);
myMethod(a: any, b?: string) {
alert(a.toString());
}
}
Only the three overloads are recognized by TypeScript as possible signatures for a method call, not the actual implementation.
In your case, I would personally use two methods with different n...
What is event bubbling and capturing?
...Selector("#div2");
div1.addEventListener("click", function (event) {
alert("you clicked on div 1");
}, true);
div2.addEventListener("click", function (event) {
alert("you clicked on div 2");
}, false);
#div1{
background-color:red;
padding: 24px;
}
#div2{
background-color:...
jQuery - Create hidden form element on the fly
...nput type="hidden" name="ipaddress" value="192.168.1.201" />');
alert('Hideen Input Added.');
});
$("#add-textarea").on('click', function(){
$('#hidden-element-test').prepend('<textarea name="instructions" style="display:none;">this is a test textarea</textarea&g...
ng-repeat finish event
...r.element(element).css('color','blue');
if (scope.$last){
window.alert("im the last!");
}
};
})
.directive('myMainDirective', function() {
return function(scope, element, attrs) {
angular.element(element).css('border','5px solid red');
};
});
See it in action in this Plunke...
Passing a function with parameters as a parameter?
...You can do this
var message = 'Hello World';
var callback = function(){
alert(this)
}.bind(message);
and then
function activate(callback){
callback && callback();
}
activate(callback);
Or if your callback contains more flexible logic you can pass object.
Demo
...
Multiple arguments vs. options object
...sObject:...,
fromIndex:...,
toIndex:...
}
function1(options){
alert(options.nodeList);
}
function2(options){
alert(options.fromIndex);
}
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How to install mongoDB on windows?
...in to one single Collection.
If you want to try out you can use below test scripts
***********************
TEST INSERT SCRIPT
*********EMPLOYEE******
db.test.save( { EmployeId: "1", EmployeFirstName: "Kodoth", EmployeLastName:"KodothLast", EmployeAge:"14" } )
db.test.save( { EmployeId: "2", Emp...
What are the best practices for JavaScript error handling?
I'm looking to start making my JavaScript a bit more error proof, and I'm finding plenty of documentation on using try , catch , finally , and throw , but I'm not finding a ton of advice from experts on when and where to throw errors.
...
“android.view.WindowManager$BadTokenException: Unable to add window” on buider.show()
...d to call an inner class and in a method within the class, I need to show AlertDialog . After dismissing it, when the OK button is pressed, forward to Google Play for purchase.
...