This question already has answers here:
"Variable" variables in JavaScript
(9 answers)
Closed 9 years ago.
I can't figure out how to use the name of a variable previously created with eval, without knowing it.
I mean:
function getName(menu_name, level){
eval("var menu_"+level+"="+menu_name);
}
Now how do I get the name of the variable I just created? Probably keep using eval, but I have to put that name into a $.post call as one of my field name.
Thanks in advice.
If level is an integer, you can treat it as a numerical index for an array:
var menu = [];
menu[level] = menu_name;
If level is anything else, you can treat it as a key for a dictionary/associative array:
var menu = {};
menu[level] = menu_name;
Then, for either of the solutions, if you want to access your menu_name, simply call menu[level].
Related
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"
This question already has answers here:
Use dynamic variable names in JavaScript
(19 answers)
Closed 7 years ago.
I have a question that I could not find the answer, or perhaps cannot phrase the way it should...
I would like to trick javascript's way of handling variables...
Let's say in php I could do something like:
$test['usr_'.$id]=826
But when I try to do the same in Javascript/jQuery:
$("#usr_rank_h").val('rank_'+id);
It will output rank_826 instead of the value of the var rank_826
The equivalent idiom in javascript is actually
var id = 826;
var test = {};
test['rank_'+id] = 826;
Which gives you back an object of the form
{
'rank_826': 826
}
PS: I'm not sure why you are using jQuery in this case, are you getting the id from an input ?
This question already has answers here:
How to use a variable for a key in a JavaScript object literal?
(16 answers)
Closed 7 years ago.
The way I usually do that,
var update = {};
update[name] = data;
update.resolved = true;
where, name is a variable.
I assume that's not the most efficient way of initialization, but it's not possible to use a variable in object notation initialization.
Other possible ways?
You can use computed property names (which is an ES6 feature, but given you tagged your question as such I assume that's not a problem):
var update = {
[name] : data,
resolved : true,
};
This question already has answers here:
"Variable" variables in JavaScript
(9 answers)
Closed 7 years ago.
im practicing javascript and i have arrays (more than 10) which have strings in it
var p = ["one","two","three","four"];
var q = [//somthing here]
and another array which is created by a function which select n store some array names for further actions
var m = ["p","q","r","s"];
how can i use element of array m as the varable/array name like:
<button onclick="testArrays(dest, m[0])">desti</button>
must have to work like this
<button onclick="testArrays(dest, p)">desti</button>
all i want to say that how can i use m[0] as a variable
im not using objects
As a variable where? If it's a property of an object you can use object[m[0]]
And if it's on the global scope you can use the window object window[m[0]]. If it's a variable inside a function you should rethink your approach. There is a way that starts with e and ends with val and you should never, ever use it.
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']);