This question already has answers here:
Is there a way to access a javascript variable using a string that contains the name of the variable?
(4 answers)
How to use a string as a variable name in Javascript? [duplicate]
(3 answers)
parse a string as an object from data attribute [duplicate]
(1 answer)
Use dynamic variable names in JavaScript
(19 answers)
Closed 9 years ago.
How can I make the code that follows to work?
var x = 'name';
and then, to use the value inside x, as it was a variable, and set it, so that if i want it to be NAME, i'll have the result:
var name = 'NAME';
Is it possible ?
Not directly, no. But, you can assign to window, which assigns it as a globally accessible variable :
var name = 'abc';
window[name] = 'something';
alert(abc);
However, a much better solution is to use your own object to handle this:
var name = 'abc';
var my_object = {};
my_object[name] = 'something';
alert(my_object[name]);
I haven't seen the rest of your code, but a better way might be to use an object.
var data = {foo: "bar"};
var x = "foo";
data[x]; //=> bar
var y = "hello";
data[y] = "panda";
data["hello"]; //=> panda
I think this is a little cleaner and self-contained than the window approach
Related
This question already has answers here:
How to use a variable for a key in a JavaScript object literal?
(16 answers)
Closed 5 years ago.
I wish to use a variable as json key in javascript
var chtid = "1234"
firebase.database().ref().set ({chtid :"hi"});
where chtid would be a variable
I tried this way but to no success
var chtid = "1234"
firebase.database().ref().set ({[chtid] :"hi"});
Any simple soulution please.
Put it on a variable first:
var obj = {};
var chtid = "1234"
obj[chtid] = "Hi";
firebase.database().ref().set (obj);
hope that helps
This question already has answers here:
Use dynamic variable names in JavaScript
(19 answers)
Closed 8 years ago.
I have a javascript variable
var varNameValue = "Name";
Now i want to create another variable using the value of varNameValue inside the name of the Other
var x(varNameValue)y = "abc";
So that my new variable name becomes
var xNamey = "abc";
Is there any way to do it. Please help.
Not directly in JavaScript. If you know the content in which it is run, then you can. For example, if this is in a browser, and it is in the global context (which maps to window), then you could do
window["x"+varNameValue+"y"] = "abc";
Similarly if it is on an object
var obj = {};
obj["x"+varNameValue+"y"] = "abc";
But just as a standalone var without any context? Nah.
var varNameValue = "Name";
eval("var x" + varNameValue + "y = 'abc';")
alert(xNamey);
Try
var obj={}
var nameValue="Name";
obj["x"+ nameValue +"y"]= "abc"
Then you can access it using obj.xNamey
This question already has answers here:
"Variable" variables in JavaScript
(9 answers)
Closed 8 years ago.
Problem with example:
Variable name: var product5519 = 10;
I can get this name in the form of a String i.e
var str = "product5519"
Is there any way to convert it into variable name so that i can use the value assigned to
product5519
I know one way to solve this problem i.e using eval(str)
If there is any another way to solve it please tell?
Once you are certain creating a global variable was the Right Thing to do, you can add your variable to the window object, like so:
window[str] = 42;
This works because variable lookups end up trying the window object if the variable was not defined in an inner scope.
It's a bit hacky but if you wanted to make a global variable you could do:
var str = "product5519";
window[str] = value;
You could then access the variable like:
window[str];
window.str;
str; // Assuming that there is no local variable already named "str"
you could do something like:
window['product5519'] = 'value'
it may be better to have an array of products, depending on the situation ofc.
You can use an associative array:
var variables = [];
variables['product5519'] = 10;
console.log(variables['product5519']);
This question already has answers here:
Accessing an object property with a dynamically-computed name
(19 answers)
jquery dynamic id
(4 answers)
Closed 8 years ago.
i need to access
objectName.myID
but the "myID" part is dynamically generated..
how do i do this?
i tried
this['objectName.'+ variable]
i'd hate to use eval...
ps
this happens in a function (local scope) by the way..
You can access Object properties in two ways:
o.propertyname
//or
o.["propertyname"]
When using the bracket notation you have to put the propertyname in quotes or else it will be interpreted as a variable name (which in your case is exactly what you want). So in your case where you have stored the name of the property as a string, the way to go would be:
var variable = "propertyname";
o[variable];
/* /\ variable is replace with it's string representation "propertyname" */
You can even call methods this way:
var o = {};
var functionname = 'toString';
o[functionname]();
You can mix both notations, your example would look like:
var obj = 'objectName';
var prop = 'myID';
this[obj][prop]
// or this is possible too:
this.objectName[prop]
Assuming propertyName is the name of a variable holding the name of the property, for example 'myId', then you can use.
objectName[propertyName]
More details in the MDN : Working with objects
This question already has answers here:
Is it possible to add dynamically named properties to JavaScript object?
(20 answers)
Closed 3 years ago.
Needing to do:
var some = {
`${foo1}_${foo2}`: bar
}
but this gives a syntax error though I must do it somehow. How?
you can suppose object as hashmap and access properties via []
var foo1 = 'a';
var foo2 = 'b';
var some = {};
some[foo1+'_'+foo2] = 'test';
console.log(some.a_b);