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How to check if object property exists with a variable holding the property name?
...')) {
// do something
}
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty
Another way is to use in operator, but you need quotes here as well:
if ('myProp' in myObj) {
// do something
}
https://developer.mozilla.org/en-US/docs/Web/Ja...
How to unset a JavaScript variable?
I have a global variable in JavaScript (actually a window property, but I don't think it matters) which was already populated by a previous script but I don't want another script that will run later to see its value or that it was even defined.
...
How does the “this” keyword work?
...at the this keyword is and how it is correctly (and incorrectly) used in JavaScript on the Stack Overflow site.
22 Answer...
How to measure time taken by a function to execute
...ds such as console.time() and console.timeEnd().
All modern browsers have JavaScript profilers built-in. These profilers should give the most accurate measurement as you do not have to modify your existing code, which could affect the function's execution time.
To profile your JavaScript:
In Ch...
How to use radio on change event?
...
Simple ES6 (javascript only) solution.
document.forms.demo.bedStatus.forEach(radio => {
radio.addEventListener('change', () => {
alert(`${document.forms.demo.bedStatus.value} Thai Gayo`);
})
});
<form name="dem...
How to pass arguments to addEventListener listener function?
... @Morfidon because the function with global variables act as closures in javascript which means they remembers the environment outside their lexical scope . If you just create different function in same environment then they will reference to same environment.
– bugwheels94
...
What does the function then() mean in JavaScript?
...
The traditional way to deal with asynchronous calls in JavaScript has been with callbacks.
Say we had to make three calls to the server, one after the other, to set up our
application. With callbacks, the code might look something like the following (assuming
a xhrGET function to...
How can I determine if a JavaScript variable is defined in a page? [duplicate]
How can i check in JavaScript if a variable is defined in a page? Suppose I want to check if a variable named "x" is defined in a page, if I do if(x != null) , it gives me an error.
...
Get the size of the screen, current web page and browser window
...
@Marco Kerwitz The worst thing is that I typed "javascript get window width" and the content of this answer was on Google. A big minus one from me.
– Maciej Krawczyk
Jun 11 '16 at 7:43
...
How do I pass variables and data from PHP to JavaScript?
I have a variable in PHP, and I need its value in my JavaScript code. How can I get my variable from PHP to JavaScript?
19 ...