I have code like this.
var key = "anything";
var object = {
key: "key attribute"
};
I want to know if there is a way to replace that key with "anything".
like
var object = {
"anything": "key attribute"
};
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7 Answers
In ES6, use computed property names.
const key = "anything";
const object = {
[key]: "key attribute"
// ^^^^^ COMPUTED PROPERTY NAME
};
Note the square brackets around key. You can actually specify any expression in the square brackets, not just a variable.
1 Comment
pascalzon
That's fine for ES6 but what about older versions (IE11 will crash on the code above)
Yes. You can use:
var key = "anything";
var json = { };
json[key] = "key attribute";
Or simply use your second method if you have the values at hand when writing the program.
Comments
On modern Javascript (ECMAScript 6) you can sorround the variable with square brackets:
var key = "anything";
var json = {
[key]: "key attribute"
};
Comments
This should do the trick:
var key = "anything";
var json = {};
json[key] = "key attribute";
Recently needed a solution how to set cookies passing the dynamic json key values. Using the https://github.com/js-cookie/js-cookie#json, it can be done easily. Wanted to store each selected option value of user in cookie, so it's not lost in case of tab or browser shutting down.
var json = {
option_values : {}
};
$('option:selected').each(function(index, el) {
var option = $(this);
var optionText = option.text();
var key = 'option_' + index;
json.option_values[key] = optionText;
Cookies.set('option_values', json, { expires: 7 } );
});
Then you can retrieve each cookie key value on each page load using
Cookies.getJSON('option_values');
Comments
Closures work great for this.
function keyValue(key){
return function(value){
var object = {};
object[key] = value;
return object;
}
}
var key = keyValue(key);
key(value);
2 Comments
Rick
HOF = Higher Order Functions.
Well, there isn't a "direct" way to do this...
but this should do it:
json[key] = json.key;
json.key = undefined;
Its a bit tricky, but hey, it works!
