We Keep Coding

Turn a string into function in JS [duplicate]

This question already has answers here:
How to execute a JavaScript function when I have its name as a string
(36 answers)
Closed 2 years ago.
My problem is simple and I couldn't find the proper answer in this forum. My bad...
I want to do that :
const dataReceived = foo;
foo(state);
How can I do that?
I read it is better to avoid eval, and I couldn't get success with new Function.
Thanks for your help!
EDIT
Thanks for your answers.
I work with React.
In my reducer, I have a create_item case.
I can reach action.category, that can be the word 'currency' or 'country'.
What I want to do is to launch either the method createCurrency or createCountry according what is inside action.category.
That's why I tried to join 'create' and 'action.category' to create a dynamic function name.
But it seems to be a poor idea...

The simplest approach is to create an object which contains an entry where:
the key is a string
the value is a function.
Example:
const myObject = {
myFunction: () => { [... DO SOMETHING...] }
}
Subsequently you will be able to invoke the function, using:
myObject.myFunction();
The above becomes more powerful when you use brackets notation.
Example:
const myString = 'myFunction';
myObject[myString]();

How to add item to object JS [duplicate]

This question already has answers here:
Is it possible to add dynamically named properties to JavaScript object?
(20 answers)
Closed 2 years ago.
I have looked all over google and i have found nothing that fits my needs. How would you add an item to an object. I basically have a string variable that i want as the key. Therefore i cant use obj.key = 'something';. I sort of want it like:
obj = {'somekey': 'somevalue'};
obj.add('someotherkey': 'someothervalue');
console.log(obj);
by obj.add() i mean someone's solution
and then console says {'somekey': 'somevalue', 'someotherkey': 'someothervalue'}
Does anyone know a way to do this. I don't care at what position it is just whether it is there. By the way i'm using node if that helps. If you have any questions on my code please ask.

Very simple:
obj["somekey"] = "somevalue";
You can also use a variable instead:
let myVariable = "somekey";
obj[myVariable] = "somevalue";
Or you just use normal object notation:
obj.somekey = "somevalue"

String to access nested value from object in array [duplicate]

This question already has answers here:
Accessing nested JavaScript objects and arrays by string path
(44 answers)
Closed 3 years ago.
I have a somewhat strange question,
I would like to know if it is possible to use a string as an entire reference to get a value from an object within an array.
This is my array:
const myArray = [
{name: 'element1', id: 'elementid1'},
{name: 'element2', id: 'elementid2'}
];
where myArray[0]["name"] returns: 'element1'
Would it be possible to have this entire reference: myArray[0]["name"] as a string: 'myArray[0]["name"]' and use it to reference to this value.
So this: getViaString returns 'element1' with the following set up:
const getViaString = 'myArray[0]["name"]';
I have set up this fiddle as it probably explains better what I am trying to do:
jsfiddle
Thanks.

You could potentially use eval() - not recommended.
const getViaString = eval("myArray[0]['name']");

yes you can do it with
const getViaString = eval('myArray[0]["name"]');

how to add key and a value to a json with same existing Key using Javascript [duplicate]

This question already has answers here:
How to add new property with same key name inside declared object?
(3 answers)
Closed 6 years ago.
I have a json variable like this
var jsondata={"key1":"val1", "key2":"val2"}
I want to push another object with same existing key, and i want that my variable will be like this
var jsondata={"key1":"val1", "key2":"val2", "key1":"val3"}
I tried jsondata["key1"] = "val3", but it didn't return the wanted result
Thank you in advance.

you cannot, as it is a map.
but you could create this json :
var jsondata={"Name":["Jhon","James"], "Age":40}

You can't use the same key in an object. Your question suggests that the logic behind your data structure is wrong.
An alternative:
Use a different field name, i've used "_Name" below, but perhaps "Second_Name" would be more appropriate. Unsure what your json data is modelling.
var jsondata={"Name":"Jhon", "Age":40, "_Name":"James"};
Or perhaps it makes sense to store an array of people, is that what you're trying to achieve? i.e. you have two people, with the names "Jhon" and "James"?
var jsondata={
"people": [
{"Name":"Jhon", "Age":40},
{"Name":"James"}
]
};

JavaScript Calling Object Syntax [duplicate]

This question already has answers here:
How can I access and process nested objects, arrays, or JSON?
(31 answers)
JavaScript property access: dot notation vs. brackets?
(17 answers)
Closed 8 years ago.
I need to know why this isn't working. My Javascript code accesses a variable in an object. But it appears not to be working, partly because I can't figure out the syntax.
var obj = {
size:"small",
big:false,
thing:true
}
alert(obj[size]);
I'm just not sure if I got the syntax right…

This will work here.
obj.size //returns small
OR
obj["size"] //returns small
OR
var my_var = "size"
obj[my_var] //returns small

You can reference object values either by:
obj["size"]
or
obj.size
However, there is an exception. For instance, if you have following object with a number key: (Note: key is still a string even if it's defined this way):
var obj = {
1: true
};
You can retrieve it's value only by using: obj["1"]
Hence, using obj.1 will cause a syntax error.
Therefore, your code works if you change it to e.g.: alert(obj["size"]); but I prefer to use console.log(obj["size"]); for debugging. At least, if you are playing with node.js as your tags indicates.
Cheers.