Is there any syntax to do something like the following
var obj = {a: this, b: this}
and get
obj = {a: 'a', b: 'b'}
asked Aug 12, 2015 at 5:57
ykay says Reinstate Monica
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3 Answers
If you want to create an object that has a bunch of keys and values equaling the same string, it's as simple as:
var obj = {};
['a','b'].forEach(function(item) {
obj[item] = item;
});
4 Comments
ykay says Reinstate Monica
I like this solution, even though I was wondering if it was possible on object creation
ykay says Reinstate Monica
By the way, in node, where I'm using this, you need to initialize the array before using forEach.
Andrew Shepherd
@ykay - Are you sure? I just tried typing
['a','b','c'].forEach(function(c) { Console.log(c); }); into node.js. It worked.ykay says Reinstate Monica
Hi Andrew, you're right, express was throwing an error if I started a line with the array but the line before wasn't closed with a semicolon
Yes! I'm not sure why you would use but here it is:
var obj = { a: 'you', b: 'they'};
var newObj = {};
for (var key in obj) {
newObj[key] = key
};
//newObj = {a: "a", b: "b"}
1 Comment
ykay says Reinstate Monica
Thanks, this seems pretty good, but I was wondering if I could do this on the object creation
You can do this:
var obj = {a: "this is A", b: "this is B"}
obj.a equals to "this is A"
obj.b equals to "this is B"
A quick snippet using this object example to add the pointer locations stored in an object:
function getMousePosition(event){
var mouse = {x: 0, y: 0};
mouse.x = event.clientX;
mouse.y = event.clientY;
Elem = document.getElementById("Elem");
Elem.innerHTML = "Simple Mouse Position by Khriztian Azuaje.<br><br>" + "X pos: " + mouse.x + ", Y pos: " + mouse.y;
}#Elem {
background:black;
text-align: center;
color:white;
padding:2px;
display: flex;
align-items: center;
justify-content: center;
height:160px;
}<body onmousemove="getMousePosition(event)">
<div id="Elem"></div>
</body>
4 Comments
SuperBiasedMan
It might help to explain a bit about why your code works.
Andrew Shepherd
Why would you go to the trouble of initializing
obj to {a: this, b: this}? Writing var obj = {} would give you identical results in the end
Khris Azuaje
@SuperBiasdMan He asked for a syntax, not how objects work. I rest assured giving a simple object syntax without explanation knowing its what he's after (in a simple way).
Khris Azuaje
I'll edit my answer to avoid unnecessary missunderstandings.
