This question already has answers here:
Using optional chaining operator for object property access
(2 answers)
Access Javascript nested objects safely
(14 answers)
Closed 7 months ago.
I want to use the following condition
if (this.solvedConflictsDetails[this.instance.instanceId][this.model.name][this.entity.entityId].solved)
The problem is that if one of the above doesn't exist in the object it will say cannot read undefined
How would you check a condition like this?
Related
This question already has answers here:
Add a property to a JavaScript object using a variable as the name? [duplicate]
(14 answers)
How to create an object property from a variable value in JavaScript? [duplicate]
(9 answers)
JavaScript object: access variable property by name as string [duplicate]
(3 answers)
Closed 2 years ago.
In JavaScript everything is object like String literal, numbers, Object...
And properties can be added to objects dynamically also, but I am adding property to object which refer to string then it seems it is not working
Following is JS code which I am running
var aVar = "some string";
console.log(aVar);
aVar.name = 'raj';
console.log(aVar.name);
Output...
hi
some string
undefined
This question already has answers here:
Self-references in object literals / initializers
(30 answers)
Can a JavaScript object property refer to another property of the same object? [duplicate]
(2 answers)
How do I reference the same Object's properties during its creation? [duplicate]
(5 answers)
How can a JavaScript object refer to values in itself? [duplicate]
(8 answers)
Can I reference other properties during object declaration in JavaScript? [duplicate]
(7 answers)
Closed 5 years ago.
var fighters = ['johnjones', 'rondarousey', 'connormcgregor', 'chuckliddel', 'demetriusjohnson'];
var warriors = {
wrestlers: ['randysavage', 'hulkhogan', 'ultimatewarrior', 'jakethesnake', 'milliondollarman'],
stable: [fighters, warriors.wrestlers]
}
I believe I can reference fighters from stable, but can I reference wrestlers from stable? In other words, how do I reference a key value pair from a later key value pair within the warriors object. Thank you for any and all help!
You cannot do that until the variable warriors is initialized. The only way is to wait and assign in the next line:
var warriors = {
wrestlers: ['randysavage', 'hulkhogan', 'ultimatewarrior', 'jakethesnake', 'milliondollarman'],
}
warriors.stable = [fighters, warriors.wrestlers]
Or use some kind of weird initialization like the one described here. Or use function constructor.
This question already has answers here:
Adding elements to object
(19 answers)
Closed 6 years ago.
I would like to know how to add/ remove properties to object at run time in javascript? How to achieve this in javascript ?
Let's say your object is myobj
then you can add a member like this
myobj.myvar = value; or myobj["myvar"] = value;
and remove it with
delete myobj.myvar; or delete myobj["myvar"];
This question already has answers here:
How to list the properties of a JavaScript object?
(18 answers)
Closed 8 years ago.
In Java it's called the keyset.
https://www.npmjs.org/package/node-hashtable
how come there is no method to return a list of all the keys?
Looking at the source there seems to be a method indexes which returna a list of the keys.
This question already has answers here:
Testing for an empty array object in JSON with jQuery
(5 answers)
Closed 8 years ago.
I have the following JSON object that is passed to one of my functions …
{"action":"setProjectAll", "application":{"proId":"new","zoomPosition":35,"scrollerPosition":0,"language":"en","timelinePosition":0}, "clips":[]}
How can I test this object for the propertie "clip" to be "[]" (empty)?
Right now in the example above it is empty, however since the object is dynamic I need to test for that property if it contains values or not.
How can that be done?
thank you
How about
if (x.clips && x.clips.length === 0)